Relationship between prolactin and infertile. Our study group consists of 150 infertile men, aged 25 to 40 years. Patients were attending infertility department at Medi- cal Baghdad Center in Iraqi. Hyperprolactinemia refers to the consistent presence of abnormally high levels of prolactin in the blood after ruling out the physiologi- cal causes of prolactin hypersecretion. The commonest causes of chronic hyperprolactinemia are a prolactinoma primary hypothyroidism, and drugs that elevate serum prolactin levels. Clinical signs and symptoms of hyper- prolactinemia are usually resolved when prolactin levels are lowered to within the normal range.