51 patients with orbital floor fractures were studied retrospectively to evaluate results in relation to time of surgical repair and fracture size. Early repair (less than 2 months) gave better results than late repair (greater than 2 months) in regard to both enophthalmos and extraocular muscle dysfunction. Large fractures (greater than one-half floor or greater than or equal to 15 fracture volume units) were most likely to be associated with significant enophthalmos after surgery. We recommend tomography when necessary to estimate fracture size, and advise early repair of large fractures, preferably within two weeks after injury. Patients with significant extraocular muscle dysfunction due to tissue entrapment, regardless of fracture size, should be repaired early, preferably within 2 weeks after injury, if improvement does not occur spontaneously by that time.