Bladder reconstruction without using the intestine remains a challenge to this day despite the development of new biomaterials and cell cultures. Human bladder engineering is merely anecdotic, and mostly in vitro and animal studies have been conducted. In our study using a porcine model, we performed a bladder augmentation using an autologous parietal peritoneum graft (peritoneocystoplasty) and determined whether the attachment of an acellular collagen-elastin matrix (Group 1) or lack of (Group 2) had better histologic and functional results. Thus far, peritoneocystoplasty has rarely been performed or combined with a biomaterial. After 6 weeks, we observed different degrees of retraction of the new bladder wall in both groups, although the retraction was lower and the histological analysis showed more signs of regeneration (neoangiogenesis and less fibrosis) in Group 1 than when compared with Group 2. No transitional cells were found in the new bladder wall in any of the groups, and no differences were observed in the functional test results. Performing a peritoneocystoplasty is an easy and safe procedure. The data supports the benefit of an acellular collagen-elastin matrix to reinforce bladder regeneration. However, in our study we observed too much retraction of the new wall and the histologic results were not acceptable to consider it an appropriate cystoplasty technique.