From 1966 to 1977, 396 men aged 25 to 89 years (mean 58) underwent 505 repairs for recurrent inguinal herniation (including bilateral defects and recurrences). Since by 1972 it was realized that the approach precluded an effective relaxing incision, when this was indicated (66 per cent) a Marlex prosthesis was used. Seventy-four patients underwent 83 repairs with this material; 26 (35 per cent) had had previous repairs for recurrence, 29 (40 per cent) underwent contralateral herniorrhpahy, whereas another 12 (16 percent) underwent bilateral repair. Fifty-five (2 of 3) protrusions were direct. None of the patients died. Although overall 110 (22 per cent) of the operations failed, only 6 of 83 hernias (7 per cent) in which Marlex was used recurred, with a mean follow-up study of 4 years. It is important to use a large enough piece of plastic and remove attenuated fascia from around the defect. No infection or extrusion occurred. Preperitoneal placement of Marlex is recommended for difficult, repeatedly recurrent inguinal hernias.