Between mid 1970 and mid 1982, 696 patients underwent 718 operations for primary inguinal hernias by the Shouldice surgical technique. Follow-up to 31 December 1983 revealed 6 recurrences, 40 patients died during the follow-up period and 37 were lost to the study. Five patients required re-operation for complications of the suture material. Polypropylene was the most efficacious of the suture materials used during the study. Duration of hospital stay and age at operation do not influence the probability of recurrence. The operation gave consistently good results when performed by either a consultant surgeon or a surgeon in training. Using the Shouldice surgical technique the probability of recurrence of the inguinal hernia at 10 years is only 1 per cent.