In 1995, changes to the United Network for Organ Sharing renal allocation system eliminated points for certain HLA matches, increased points for waiting time and for pediatric patients, and extended the mandatory share rule to include the zero-antigen mismatch. We analyzed data, from the period December 1993 to August 1996, on 393 donors, 348 kidney-only cadaveric transplants, and 615 patients ranked first or second on the allocation lists generated for each donor, to assess the effect of the changes in the point system. There was an appreciable (46%) but not significant increase in the frequency of transplants occurring under the mandatory share rule, with a greater relative increase seen in African-Americans than in Caucasians. Recipients of transplantsnotfalling under the mandatory share rule had an increased average waiting time but no increase in sensitization or HLA mismatch, whereas patients ranked at the top of the allocation list had higher levels of sensitization but no increase in waiting time. There was an appreciable increase in the percentage of transplants occurring in African-Americans. Of the various changes we observed, only those involving the mandatory share rule could be attributed to changes in the allocation system, whereas others paralleled changes in the composition of our local waiting list.