PURPOSE: A hamate body coronal fracture is well known as a very rare fracture in the carpal bones and is also hard to diagnose in initial stage due to the bone's architecture. We report our experience in treatment of such a fracture, and we present a review of the relevant literatures. METHODS: Four patients who experienced hamate body coronal fractures from October 2006 to October 2013 were enrolled in this study. One patient also had an associated Capitate fracture, and two patients had associated dislocations of the 4th metacarpal joint. We performed open reduction and mini-screw fixation on the four patients. In addition, a K-wire was fixed for the two patients with dislocations. RESULTS: The average follow-up period was 24.5 months after surgery, and bone union was observed at the 8th week after surgery. We confirmed that bone union had been completed for all the patients, and functional tests showed that joint motion was in the normal range without complications. CONCLUSION: When a patient has consistent pain on the ulnar side of the wrist, a hamate fracture should be suspected. Computer tomography is better than a simple X-ray scan for confirming the diagnosis of a hamate body coronal fracture. An open reduction and mini-screw fixation led to a good result.