Objective: To determine the effect of adult cardiac transplant center practice patterns within a single organ procurement organization on access to donors and survival for patients listed as United Network of Organ Sharing (UNOS) status 1. Methods A total of 662 patients listed (January 1, 1992, through December 31, 1995) as UNOS status 1 for heart transplantation by the 4 adult cardiac transplant centers in an organ procurement organization were analyzed in a retrospective cohort study to determine differences in clinical outcomes. Results The specific center at which an individual was listed as UNOS status 1 was a significant independent predictor of receiving a transplant (odds ratios for 3 centers vs center with highest likelihood = 0.73, 0.64, 0.35, respectively; P <.01). Only 1 center had a significantly increased mortality rate compared with the other centers (odds ratio 2.03, P <.01). Conclusion Within a single regional organ procurement organization, cardiac transplant centers demonstrate significant variability in the likelihood of transplantation and survival for patients listed as UNOS status 1. (Am Heart J 2000;140:443-50.)