The present invention relates to a method and composition for preventing surgical adhesions during surgery. Tissue surfaces and/or surgical articles involved in the surgery are separated by a biomaterial provided in the form of a non-crosslinked, decellularized and purified mammalian tissue (e.g. bovine pericardium). The biomaterial effectively inhibits fibrosis, scar formation, and surgical adhesions, while also serving as a scaffold for recellularization of the tissue site.