We undertook a prospective study of traumatic hyphema during the years 1970 through 1972 to compare the effects of medical management and surgical evacuation in the more severe hyphemas. A protocol for sutdy of the two regimens enabled us to compare the results of therapy. The findings indicate that medical management is preferable for the initial 4 days in major hyphemas. Surgical intervention does not offer improvement in the poor prognosis of total hyphemas during this early period. The incidence of complications and the incidence of permanent poor visual results are higher in surgically treated patients than in those managed medically. Surgical intervention should be reserved for cases showing: (1) microscopic corneal blood staining; (2)total hyphemas with intraocular pressures of 50 mm Hg or more for 5 days (to prevent optic nerve damage); (3) hyphemas that are initially total and do not resolve below 50% at 6 days with intraocular pressures of 25 mm Hg or more (to prevent corneal blood staining); and (4) hyphemas that remain unresolved for 9 days (to prevent peripheral anterior synechiae). A brief review of problems that may be encountered in the various forms of surgical management is included in an effort to prevent repeating similar pitfalls.