The incidence of endometriosis in the general population has been reported to range from 4% to 32%. A more realistic figure is probably 7.5%. An incidence of 7.4% was found in 42 of 566 multiparous women undergoing tubal sterilization at Baylor College of Medicine, Houston. Twelve of the 42 (29%) were less than five months postpartum. Hispanics had an incidence of endometriosis similar to that of whites and blacks. Indigent status had no bearing on the presence of endometriosis. A higher incidence of spontaneous abortion was found in patients with endometriosis, but the difference was not statistically significant.