This study compared the frequency of chronic pain after laparoscopic (totally extraperitoneal patch, TEP) and open (Lichtenstein) repairs.A randomized multicentre study with 5 years' follow-up was conducted on men with a primary inguinal hernia. Chronic pain was categorized as mild, moderate or severe by blinded observers. A subgroup analysis was performed on 121 patients who experienced moderate or severe pain at any time during follow-up.Overall, 1370 of 1512 randomized patients underwent surgery, 665 in the TEP and 705 in the Lichtenstein group. The total incidence of chronic pain was 11·0 versus 21·7 per cent at 1 year, 11·0 versus 24·8 per cent at 2 years, 9·9 versus 20·2 per cent at 3 years and 9·4 versus 18·8 per cent at 5 years in the TEP and Lichtenstein groups respectivel...