We analysed the 49 fractures of radial styloid process which were treated at St. Mary's hospital since 1980, and tried to confirm the fracture type and mechanisms, their combined injuries around the affected wrist and to discuss the method of treatment. The results were as follows. l. Out of total 49 fractures, 38 cases(77.6%) were oblique fractures and the other 11 cases(22.4%) were transverse fractures in shape. 2. Twenty-four cases(49.0%) out of 49 fractures had been accompanied with various combined injuries around the affected wrist, i.e., 8 cases with lunar or perilunar dislocation, 6 cases with scapholunate dissociation, 3 cases with carpal subluxation and 7 cases with ulnar styloid process fracture. 3. Seven cases(41.2%) out of total 17 cases with combined wrist instabilities were missed in diagnosis initially, treated later and their results were not so good because of chronic wrist pain and ligamentous instabilities. 4. Sixteen patients(32.7%) were treated surgically, that is, open reduction, primary ligaments repair and K-wire fixation in 11 cases, reconstruction of torn carpal ligaments in 3 cases and proximal carpectomy in 2 cases. The oblique fracture of radial styloid process associated with scapho-lunate dissociation will occur commonly, but easily missed in initial diagnosis which could be the cause of chronic wrist pain and ligamentous instabilities later. So careful evaluation of initial wrist x-rays and also the long-term follow up should b done.