AbstractThe association between colorectal cancer and primary hyperparathyroidism has been reported as case reports in the literature. There are few data regarding the molecular explanation of such coexistence. Here we report a case with synchronous pathologies of primary hyperparathyroidism and colorectal cancer. Furthermore, the patient has a positive family history of the same two pathologies in one of his first-degree relatives. We reviewed the literature to clarify and explain the relationship between these two diseases. We aimed to shed light on the coexistence of such conditions and to clarify if there is a relation between them or if it is just a coincidence.