Little is known about the outcomes among solid organ transplant recipients with a pretransplant cancer diagnosis. We used linked data from the Scientific Registry of Transplant Recipients with 33 US cancer registries. Cox proportional hazards models assessed associations of pretransplant cancer with overall mortality, cancer-specific mortality, and development of a new posttransplant cancer. Among 311 677 recipients, the presence of a single pretransplant cancer was associated with increased overall mortality (adjusted hazard ratio aHR, 1.19; 95% CI, 1.15-1.23) and cancer-specific mortality (aHR, 1.93; 95% CI, 1.76-2.12); results for 2+ pretransplant cancers were similar. Cancer-specific mortality was not significantly increased for uterine, prostate, or thyroid cancers (aHRs were 0.83, 1.22, and 1.54, respectively) but strongly elevated for lung cancer and myeloma (aHRs were 3.72 and 4.42, respectively). A pretransplant cancer diagnosis was also associated with increased risk of developing posttransplant cancer (aHR, 1.32; 95% CI, 1.23-1.40). Among 306 recipients whose cancer death was confirmed by cancer registry data, 158 deaths (51.6%) were from a de novo posttransplant cancer and 105 (34.3%) from the pretransplant cancer. Pretransplant cancer diagnoses are associated with increased mortality after transplantation, but some deaths are related to posttransplant cancers and other causes. Improved candidate selection and cancer screening and prevention may reduce mortality in this population. Display omitted