The objective of this study was to document maturation and failure rates in a large homogeneous series of arteriovenous fistulas (AVFs). Between January 1, 1996, and December 31, 2001 (60 months), a single surgeon (AFS) in 1 academic medical center, constructed 374 AVFs. In this series, all AVFs were developed in vessels that had not undergone previous vascular access surgery. Recently, a retrospective review of these records revealed that 291 subjects had had complete follow-up for at least 3 months, and they constitute the material for this study. AVFs were considered a failure if an early occlusion/thrombosis occurred, if in 3 months the AVF had not matured on clinical examination, or if cannulation in the dialysis center was not feasible. A total of 91 AVFs did not mature, for an overall failure rate of 31%. An evaluation of failure rates indicated rates in females were higher than in males (41% versus 27%). Other risk factors, including HIV+ status, hypertension, and diabetes, demonstrated minimal failure differences (33%, 31%, and 36%, respectively).