Twelve female microminipigs with normal bladder capacity underwent laparoscopic bladder seromyotomy, Three other female microminipigs were added to the study as controls. Urodynamic studies and cystograms were performed preoperatively and at 2 and 4 months after a laparoscopic bladder seromyotomy. Histologic studies of the treated bladders were performed when the animals were euthanized at 4 months. The operation was completed in all 12 test animals. There was no significant difference in bladder capacity or leak-point pressure between the 12 seromyotomy and the 3 control bladders at any time point. Histologically, over the seromyotomy site, the urothelium remained intact; however, the muscularis was attenuated, and a thin layer of fibrotic tissue replaced the normal serosal covering of the bladder, Laparoscopic bladder seromyotomy can be performed reliably in the porcine animal model, Not surprisingly, no significant changes in bladder capacity or bladder compliance were seen in our study of normal bladders. An animal model of a neuropathic contracted bladder is needed to assess more accurately the physiological impact of laparoscopic seromyotomy.