Surgical repair of diseased or damaged endogenous connective tissue can be accomplished using a tissue graft formed from a delaminated segment of intestinal tissue. The tissue graft comprises the intestinal tunica submucosa, muscularis mucosa and stratum compactum delaminated from the tunica muscularis and the luminal portion of the tunica mucosa. The graft can be conditioned by stretching and formed as a multilayer composition for high tensile strength and resistance to tearing at its points of attachment to existing physiological structures.