Visual improvement was achieved in 62% of 100 consecutive patients with ocular trauma treated by pars plana vitrectomy. Anterior segment injuries had a better prognosis than posterior segment injuries, and retinal detachment was a poor prognostic sign. Patients undergoing vitrectomy during the two weeks after injury had a better visual prognosis than those who had delayed vitrectomy. Pars plana vitrectomy has increased the recovery rate in traumatized eyes which previously were deemed inoperable and frequently were enucleated. Most such eyes have intraocular fibrocellular proliferations, resulting in traction retinal detachments, cyclitic membranes, and phthisis, as documented in clinicopathological and experimentally produced specimens of penetrating ocular trauma. Vitrectomy can interrupt this sequence, if performed one to 14 days after injury, by removing the vitreous scaffold onto which proliferation occurs, together with the elements of hemorrhage, damaged lens, vitreous, and foreign material which may incite proliferation. We believe four to ten days after injury to be the optimal time for vitrectomy to avoid the hazards of immediate intervention, while removing damaged tissue before serious sequenlae occur.