There are no objective data available on the relative strengths of inguinal hernia repairs. The aim of this randomized controlled study was to measure the force required to disrupt laparoscopic and open mesh repairs in a porcine model. Eleven pigs had inguinal hernia repair following randomization to an open mesh group (n = 5) or a transabdominal preperitoneal laparoscopic group (n = 6). Four weeks after operation the pigs were killed and the pelvic girdles were mounted in a test jig on a mechanical testing machine. The applied disruption forces were measured and recorded. Mean(s.d.) force required to disrupt the normal inguinal canal (n = 11) was 68·6(30·1) N with no difference between groups. The open mesh repair required 110·3(41·4) N and the laparoscopic mesh 220·0(95·2) N. Both open and laparoscopic mesh repairs were stronger than the normal side (P<0·03). The laparoscopic mesh repair was stronger than the open mesh repair (P = 0·04). This model provides a standardized method for mechanically testing inguinal hernia repairs in pigs. It confirms that both open and laparoscopic mesh hernia repairs are stronger than the non-herniated normal side at 4 weeks after operation. Laparoscopic mesh repair is stronger than open mesh repair. The weakest points of the repairs correlate well with those identified in clinical reports.