There is frequently a need for dural grafts to cover defects resulting from retraction, shrinkage, or excision following neurosurgical procedures. Several materials have been evaluated both experimentally and clinically, and then discarded. Collagen, in its various forms, continues to be an area of intense interest. In this study the authors examined the suitability of collagen sponge to effect dural repair. In a 5-year clinical study 102 collagen sponge implants were examined macroscopically and histologically. Graft encapsulation, neomembrane formation, delayed hemorrhage, and foreign body reactions were not found. The porous nature of the collagen sponge encouraged fibroblastic ingrowth and dural repair. Meningocerebral adhesions were present in 11 patients, all of whom had required significant cortical resection or had pia-arachnoid disruption during the initial surgery. Inflammatory cells were seen only in response to infection. Postoperative cerebrospinal fluid leaks developed in only three of 67 patients who underwent an intradural posterior fossa procedure. In a prospective arm of the study involving 459 patients, the wound infection rate using collagen sponge was 6.1%, which compared favorably (p = 0.67) with the 5.7% rate in a similar group of 637 patients in whom collagen sponge had not been used.