While infection and acute rejection continue to be the most frequent cause of early postoperative mortality, chronic rejection including both coronary vasculopathy and unspecific myocardial allograft failure and side effects of immunosuppressive therapy determine late survival and quality of life. Some data are presented of a systematic program for long-term follow-up of cardiac transplant recipients with particular emphasis on coronary vasculopathy and modern concepts in rejection detection and control. Infections remain a notable source of morbidity and mortality. The importance of continued efforts to prevent infection even in the Cyclosporin era has to be emphasized. Tricuspid insufficiency is influenced by the mismatch of recipient and donor heart size. Intraoperative adaptation of the recipient pericardium to the size of the donor heart reduces the magnitude. Unspecific graft failure has been observed to occur at an incidence of 8% three years after transplantation. Three types of rejection can be distinguished after heart replacement, the hyperacute rejection as a rare complication precipitated by preformed recipient antibodies to donor antigens, the acute rejection as a major risk factor for survival in the postoperative first year, and, finally, the chronic rejection which is an important factor for long-term survival and quality of life. Considering the detection and classification of the acute rejection, a semiquantification is advantageous because of its therapeutic relevance. The chronic rejection is characterized by vascular abnormalities, interstitial changes, and myocardial alterations. Of these, the vascular component is the most important clinically. The incidence of this coronary vasculopathy, taking all forms visible angiographically, is about 30-40% of surviving patients three years after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)