OBJECTIVE: To study the occurrence and types of neoplasms developed by patients who underwent an orthotopic cardiac transplantation under the Program of Cardiac Transplantation of Escola Paulista de Medicina, Federal University of São Paulo. METHODS: This is an observational study of 106 patients who underwent orthotopic cardiac transplantation from November 1986 to September 2002 and survived at least thirty days following the procedure. The triple immunosuppressive regimen given included cyclosporin A, azathioprine and a corticosteroid agent. Only two patients received OKT3 in addition to the regimen established. Mean follow-up was 61.4 months (ranging from two months to 192 months). RESULTS: Twenty-three patients (21.3%) developed neoplasms--56.5% of these were skin neoplasm, 30.1%, solid tumors, and 13.4% of post-transplant lymphoproliferative disease (PTLD). Mean interval between transplantation and diagnosis of neoplasm was: 54.9 months for skin neoplasm; 24.8 months for solid tumors and 70.3 months for PTLD. CONCLUSION: Malignant neoplasms are relatively common in the population studied. Skin cancer was the most common type compared to the other types of neoplasms. Solid tumors were more frequently diagnosed than the lymphoproliferative diseases in the population examined.