| ULTRASAFE LIMITED | Private company limited by shares | Live |
| Ultrasaw Hong Kong Limited | Private company limited by shares | Dissolved |
| ULTRASCOPE DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| ULTRASHAPE LIMITED | Private company limited by shares | Dissolved |
| ULTRA-SHARP LIMITED | Private company limited by shares | Dissolved |
| Ultrashield Limited | Private company limited by shares | Dissolved |
| ULTRASIA LIMITED | Private company limited by shares | Live |
| ULTRASKY LIMITED | Private company limited by shares | Dissolved |
| ULTRA-SMART LIMITED | Private company limited by shares | Dissolved |
| ULTRA-SMOOTH LIMITED | Private company limited by shares | Live |
| ULTRA-SOLID LIMITED | Private company limited by shares | Dissolved |
| Ultrasolis Limited | | Live |
| ULTRA-SONG KARAOKE SOUND SYSTEM (H.K.) LIMITED | Private company limited by shares | Live |
| ULTRASONIC COMPANY LIMITED | Private company limited by shares | Dissolved |
| ASIA ULTRASONIC LIMITED | Private company limited by shares | Live |
| DICKSON & ULTRASONIC PCB COMPANY LIMITED | Private company limited by shares | Dissolved |
| SANHO ULTRASONIC ENGINEERING LIMITED | Private company limited by shares | Live |
| ULTRASONIC INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| TUNG PO ULTRASONIC TECHNOLOGY COMPANY LIMITED | Private company limited by shares | Live |
| ULTRASONICA LIMITED | Private company limited by shares | Live |
| SJP Ultrasonics Limited | Private company limited by shares | Live |
| Ultrasonics Limited | | Live |
| BRANSON ULTRASONICS (ASIA PACIFIC) CO. LIMITED | Private company limited by shares | Live |
| Cheersonic Ultrasonics Co., Limited | Private company limited by shares | Live |
| ULTRASONICS ENGINEERING CO., LIMITED | Private company limited by shares | Live |
| Pyrocks Ultrasonics Company Limited | | Live |
| PZFlex Ultrasonics Limited | Private company limited by shares | Live |
| RINCO ULTRASONICS (HONG KONG) LIMITED | Private company limited by shares | Live |
| Hong Kong Endoscopic Ultrasonography Society Limited | Company limited by guarantee | Live |
| ULTRASOUND BOOTS (ASIA) LIMITED | Private company limited by shares | Live |
| ULTRASOUND BOOTS LIMITED | Private company limited by shares | Live |
| ULTRA-SOUND DIAGNOSTICS LIMITED | Private company limited by shares | Dissolved |
| Focused Ultrasound Hong Kong Foundation Limited | Company limited by guarantee | Live |
| ULTRASOUND INDUSTRIAL LIMITED | Private company limited by shares | Dissolved |
| ULTRASOUND INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| Focused Ultrasound Medical Research Foundation Limited | Company limited by guarantee | Live |
| Focused Ultrasound Surgery Association Limited | Company limited by guarantee | Live |
| Ultrasound Technology Co., Limited | | Live |
| GENERAL ULTRASOUND TECHNOLOGY LIMITED | Private company limited by shares | Live |
| PACIFIC ULTRASOUND TECHNOLOGY LIMITED | Private company limited by shares | Dissolved |
| ULTRASOUND TRADING LIMITED | Private company limited by shares | Live |
| Ultrasound Wondering Inc Limited | Private company limited by shares | Live |
| ULTRASOURCE COMPANY LIMITED | Private company limited by shares | Live |
| Ultraspeed Networks HK Limited | Private company limited by shares | Live |
| ULTRASPEX LIMITED | Private company limited by shares | Dissolved |
| ULTRA-SPLENDID LIMITED | Private company limited by shares | Dissolved |
| ULTRASTABLE LIMITED | Private company limited by shares | Dissolved |
| ULTRASTAR LIMITED | Private company limited by shares | Dissolved |
| Ultrastar HQ Limited | | Live |
| ULTRA-STEADY LIMITED | Private company limited by shares | Dissolved |
| ULTRA-STRONG LIMITED | Private company limited by shares | Dissolved |
| ULTRASUPREME LIMITED | Private company limited by shares | Live |
| ULTRASYS COMPANY LIMITED | Private company limited by shares | Dissolved |
| ULTRASYS.COM LIMITED | Private company limited by shares | Dissolved |