The role of antibiotics was investigated prospectively in 91 open fractures of the finger. Antibiotics were administered to alternate patients with open phalangeal fractures. Only finger fractures distal to the metacarpophalangeal joint were included. Both groups were treated with aggressive surgical irrigation and debridement. In four patients in each group clinical signs of infection eventually developed; osteomyelitis did not develop in any patients, and no secondary surgical procedures were required in either group. This data indicates that vigorous irrigation and debridement is adequate primary treatment for open phalangeal fractures in fingers with intact digital arteries.