A total number of 18 apparently healthy adult male mongrel dogs were used to evaluate tunica vaginalis propria as an autologus graft for bladder augmentation. Dogs were assigned into two groups. The first one, (control group), was exposed to primary incisional closure of the bladder without wall augmentation. The second group, in which the bladder was reconstructed with a sheet of the tunica vaginalis propria. The results of clinical examination revealed that all cases appeared normal with the presence of frequent urination in the control group. Five cases were died (three from control group and two cases from augmented group). Cystography showed small size of the bladder in the control group, while normal size in the augmented group. Grossly, decreased diameter of the graft indicated its shrinkage. It changed into remnant at 12weeks postoperatively. Microscopically, all layers of the bladder wall were observed in the augmented portion at 12 weeks postoperatively. It could be concluded that, the using of tunica vaginalis propria in male dogs has the advantage of using readily available autologous graft for bladder wall reconstruction.