In this observational and multicenter study, that included all patients who underwent a heart transplantation (HT) in Spain from 1984 to 2018, we analyzed the incidence, management, and prognosis of colorectal cancer (CRC) after HT. Of 6,244 patients with a HT and a median follow-up of 8.8 years since the procedure, 116 CRC cases (11.5% of noncutaneous solid cancers other than lymphoma registered) were diagnosed, mainly adenocarcinomas, after a mean of 9.3 years post-HT. The incidence of CRC increased with age at HT from 56.6 per 100,000 person-years among under 45 year olds to 436.4 per 100,000 person-years among over 64 year olds. The incidence rates for age-at-diagnosis groups were significantly greater than those estimated for the general Spanish population. Curative surgery, performed for 62 of 74 operable tumors, increased the probability of patient survival since a diagnosis of CRC, from 31.6% to 75.7% at 2 years, and from 15.8% to 48.6% at 5 years, compared to patients with inoperable tumors. Our results suggest that the incidence of CRC among HT patients is greater than in the general population, increasing with age at HT.