| MARIA'S MEDICAL BEAUTY & SPA COMPANY LIMITED | Private company limited by shares | Dissolved |
| Mark Medical Company Limited | Private company limited by shares | Live |
| MARK TO MARKET MEDICAL LIMITED | Private company limited by shares | Live |
| Mars Medical Limited | Private company limited by shares | Live |
| MARSHA MEDICAL LIMITED | Private company limited by shares | Live |
| MARYKNOLL MEDICAL AND WELFARE ASSOCIATION LIMITED -THE- | Company limited by guarantee | Live |
| HK MEDICAL MASK LIMITED | Private company limited by shares | Live |
| GOMEDICO MEDICAL MASK FACTORY LIMITED | Private company limited by shares | Live |
| MAST Medical Group Limited | Private company limited by shares | Live |
| MASTER MEDICAL LIMITED | Private company limited by shares | Live |
| MASTER K MEDICAL CENTRE LIMITED | Private company limited by shares | Live |
| Master Chinese Medical Clinic Limited | Private company limited by shares | Live |
| TS Idea Medical Material Co. Limited | | Live |
| CHINA MEDICAL MATERIALS INDUSTRY ASSOCIATION LIMITED | Private company limited by shares | Live |
| Maxlect Medical LIMITED | | Live |
| MEDAES MEDICAL LIMITED | Private company limited by shares | Live |
| MedHealth Medical Limited | | Live |
| MEDI PLUS MEDICAL CENTRE LIMITED | Private company limited by shares | Live |
| HK MEDI43 MEDICAL LIMITED | Private company limited by shares | Live |
| MedicHealth Medical Technology Company Limited | Private company limited by shares | Live |
| Medico Medical Devices Co., Limited | | Live |
| MEDIFAST MEDICAL CENTER LIMITED | Private company limited by shares | Live |
| MEDIPLUS MEDICAL COMPANY LIMITED | Private company limited by shares | Live |
| Medisun Medical Center Limited | Private company limited by shares | Live |
| Medisun Precision Medical Center Limited | Private company limited by shares | Live |
| Medisun Regenerative Medical Center Limited | Private company limited by shares | Live |
| MEDITECH MEDICAL COMPANY LIMITED | Private company limited by shares | Dissolved |
| MEDITEK MEDICAL LIMITED | Private company limited by shares | Dissolved |
| MEGA MEDICAL PROMOTIONAL COMPANY LIMITED | Private company limited by shares | Live |
| MEGATOP MEDICAL TECHNOLOGIES COMPANY LIMITED | Private company limited by shares | Live |
| MEGATOP MEDICAL TECHNOLOGIES SERVICE LIMITED | Private company limited by shares | Live |
| M.E.H. MEDICAL DEVICES COMPANY LIMITED | Private company limited by shares | Live |
| MEIYUN MEDICAL GROUP LIMITED | Private company limited by shares | Live |
| MEKON HK MEDICAL LIMITED | | Live |
| Mena Medical Limited | | Live |
| MENGSHIRUI MEDICAL RESEARCH CENTER LIMITED | Private company limited by shares | Live |
| MEONTAI MEDICAL LIMITED | Private company limited by shares | Dissolved |
| Mercer Medical Limited | Private company limited by shares | Live |
| GRAND MERIT MEDICAL COMPANY LIMITED | Private company limited by shares | Live |
| Meta Medical Limited | | Live |
| MetaLab Medical Beauty Group Limited | | Live |
| Metro Medical Company Limited | Private company limited by shares | Live |
| Metro Medical Centre Limited | Private company limited by shares | Live |
| Mevion Medical Systems Limited | Private company limited by shares | Live |
| MEYCHSON MEDICAL LIMITED | Private company limited by shares | Live |
| MicroPort Medical (Hong Kong) Limited | Private company limited by shares | Dissolved |
| MILES MEDICAL COMPANY LIMITED | Private company limited by shares | Live |
| MILESTONE MEDICAL LIMITED | Private company limited by shares | Dissolved |
| MILLENNIUM MEDICAL LIMITED | | Live |
| Million Rivers Medical Centre Limited | | Live |
| YUE SAM MIND MEDICAL ASSISTANCE LIMITED | | Live |
| HAPPY MIND MEDICAL CENTER LIMITED | Private company limited by shares | Live |
| MINDS MEDICAL LIMITED | Private company limited by shares | Live |
| Minful Medical Limited | Private company limited by shares | Live |
| MiracleMed Medical Company Limited | Private company limited by shares | Dissolved |
| MIRAE MEDICAL CO., LIMITED | Private company limited by shares | Live |
| MIRCARE MEDICAL CARE COMPANY LIMITED | Private company limited by shares | Dissolved |
| MISSION MEDICAL CARE LIMITED | Private company limited by shares | Dissolved |
| MITSUBISHI TANABE MEDICAL COMPANY LIMITED | Private company limited by shares | Live |
| MIUSEE MEDICAL LIMITED | | Live |
| Cos Max Medical Centre (MK) Limited | | Live |
| Charming Medical (MK) Limited | | Live |
| HK M-LINK MEDICAL SERVICE COMPANY LIMITED | Private company limited by shares | Live |
| MODERN MEDICAL BLOC LIMITED | Private company limited by shares | Dissolved |
| Modern Chinese Medical Centre Limited | Private company limited by shares | Live |
| MODERN GENERAL MEDICAL MAGAZINE CO., LIMITED | Private company limited by shares | Live |
| Modern Medical Group Limited | Private company limited by shares | Live |
| MODERN CHINESE MEDICAL GROUP LIMITED | Private company limited by shares | Live |
| Modern (Shatin) Medical Centre Limited | Private company limited by shares | Live |
| Modern Medical Solutions Limited | | Live |
| MODERN MEDICAL TECHNOLOGY LIMITED | Private company limited by shares | Dissolved |
| MOKER (ASIA) MEDICAL CONSULTING CO., LIMITED | Private company limited by shares | Live |
| Molecular Medical Limited | Private company limited by shares | Live |
| Medical Monitoring Solutions Co. Limited | Private company limited by shares | Live |
| Moon Sky Medical Company Limited | | Live |
| Tokyo morinaga medical service Limited | Private company limited by shares | Live |
| MOUNT SINAI MEDICAL GROUP LIMITED | Private company limited by shares | Dissolved |
| Ms&D Medical Company Limited | | Live |
| FRANCE MULTI-PURPOSE CURE MEDICAL LIMITED | Private company limited by shares | Dissolved |
| Medical Musicians Hong Kong Limited | 擔保有限公司 | Live |
| Beauty Myth Medical Centre Limited | Private company limited by shares | Live |
| NAHL medical co., Limited | Private company limited by shares | Live |
| Nathan Medical Limited | Private company limited by shares | Live |
| China National Machinery Medical Group Limited | | Live |
| SPINOTHERAPY NATUROPATHIC MEDICAL LIMITED | Private company limited by shares | Live |
| BEAME Medical Technology (NC) Limited | | Live |
| NELSON MEDICAL CENTRE LIMITED | Private company limited by shares | Live |
| Neolife Medical Group Limited | Private company limited by shares | Live |
| NephroSave Medical Care Limited | Private company limited by shares | Live |
| MHC Medical Network Limited | Private company limited by shares | Dissolved |
| SCG Medical Network Limited | | Live |
| CYBER MEDICAL NETWORK LIMITED | Private company limited by shares | Live |
| ASIA MEDICAL NETWORKS LIMITED | Private company limited by shares | Dissolved |
| EASTERN MEDICAL NETWORKS LIMITED | Private company limited by shares | Live |
| EHEALTHY.CARE MEDICAL NETWORKS LIMITED | Private company limited by shares | Live |
| Euro Medical Networks Limited | Private company limited by shares | Live |
| GBA Cardiovascular and Neurovascular Medical Centre Limited | Private company limited by shares | Live |
| Newa Medical Limited | Private company limited by shares | Live |
| Newa Medical Aesthetics Limited | Private company limited by shares | Live |
| NewLife Medical Consultancy Limited | | Live |