Hyperprolactinemia corresponds to an increase in the level of prolactin, the symptoms vary according to the sex and the length of time the disease has been present. It can be secondary to several situations: functional or organic. Hypothyroidism is considered to be one of the classic functional causes of hyperprolactinemia. On the other hand, prolactin is known for its stimulating effects on the immune system. Therefore, hyperprolactinemia is incriminated in the occurrence of autoimmune diseases, especially hypothyroidism. We report an observation of hyperprolactinaemia revealing the rare association of peripheral hypothyroidism and a macroprolactinoma.