In this study we investigated whether the duration of ischemia before heart transplantation was related to coronary arteriopathy. Heterotopic cardiac isografts were done in 24 Lewis rats. Group 1 hearts (n = 4) were transplanted immediately after harvesting. Hearts in groups 2 (n = 8), 3 (n = 6), and 4 (n = 6) were implanted after preservation at 4 degrees C for 1, 2, or 3 hours, respectively. No immunosuppressive drugs were given. After 120 days, grafts were removed and evaluated by means of light microscopy for coronary artery intimal proliferation. Minimal intimal thickening was noted throughout, and no differences among the groups were found. Pretransplant ischemia in the absence of other factors does not cause coronary arteriopathy after heart transplantation.