The purported advantage of lightweight large-pore meshes is improved biocompatibility that translates into lesser postoperative pain and earlier rehabilitation. However, there are concerns of increased hernia recurrence rate. We undertook a prospective randomized clinical trial to compare early and late outcome measures with the use of a lightweight (Ultrapro) mesh and heavyweight (Prolene) mesh in endoscopic totally extraperitoneal (TEP) groin hernia repair. A prospective study was performed on 402 patients (191 in Ultrapro and 211 in Prolene group) with bilateral groin hernias who underwent endoscopic TEP groin hernia repair from March 2006 to June 2007. All operations were performed by five consultants following a standardized operative protocol. Chronic groin pain and hernia recurrence were evaluated as primary outcome measures. Secondary outcome measure were early postoperative pain, operative time, number of fixation devices required to fix the mesh, return to normal daily activities of work, seroma, and testicular pain. At 1-year follow-up, incidence in Ultrapro versus Prolene group for chronic groin pain was 1.6% vs. 4.7% (p = 0.178) and recurrence was 1.3% vs. 0.2% (p = 0.078). In Ultrapro versus Prolene group, mean visual analogue score for postoperative pain at day 7 was 1.07 vs. 1.31 (p = 0.00), mean return to normal activities was 1.82 vs. 2.09 days (p = 0.00), and mean number of fixation devices per patient required to fix the mesh was 4.22 vs. 4.08 (p = 0.043). Lightweight meshes appear to have advantages in terms of lesser pain and early return to normal activity. However, more patients had hernia recurrence with lightweight meshes, especially for larger hernias. We surmise that the lightweight meshes have greater tendency to get displaced from their intended position during desufflation at the conclusion of endoscopic TEP repair.