Carpometacarpal (CMC) joint fracture-dislocations are uncommon, and diagnosis can be easily missed when serious injuries to other structures have occurred at the same time or when radiographs at initial evaluation are inadequate. This article describes two cases of dorsal fracture-dislocation of CMC joints easily missed when diagnosing a concurrent metacarpal fracture. Open reduction and internal fixation was performed for CMC joints and metacarpal fracture. The patients were placed in a plaster splint postoperatively to immobilize the wrist and CMC joints. After treatment, the patients returned to work with no pain and had nearly normal wrist motion and strength.