Proximal open comminuted fractures of the fourth metatarsal bone (Mt IV) in eight horses were treated by complete removal of the affected bone and antimicrobial therapy. Two horses had concurrent septic arthritis of the tarsocrural or distal tarsal articulations, and five horses had radiographic evidence of osteomyelitis and sequestration of the affected bone. Five horses became athletically sound for their intended use, two horses with septic arthritis had residual lameness but were pasture sound, and one horse was lost to follow-up. Excision of the entire bone appears to be an acceptable treatment of open comminuted fractures of the proximal one-third of Mt IV that do not respond to more conservative modes of therapy.