Abstract: Hyperprolactinemia is the most common endocrine disorder of the hypothalamic-pituitary axis. We have not any documented data about frequency of various etiologies of hyperprolactinemia in our region. For determination of the pattern of presentation and distribution of causes of hyperprolactinemia the presenting study were designed and conducted. In a descriptive study, we extract medical records of patient presented to our clinic with diagnosis of hyperprolactinemia between first day of 2001 until last day of 2006. At this time interval we found 127 patients with diagnosis of hyperprolactinemia, of which 14 excluded due to absence of sufficient data for determination of etiology. The remaining 113 subjects` data were collected and analyzed. In our study, 27 (23%) of patients were male and 86 (76%) were female. Grater than 63% of subjects had 20-40 years old. The presenting sings and symptoms of patients were in order of frequency: Menstrual abnormalities, galactorrhea, infertility, headache, visual disturbances and sexual dysfunction. Pituitary adenoma was the most frequent etiology of hyperprolactinemia in our subjects. Other causes of hyperprolactinemia were: Idiopathic hyperprolactinemia, hypothyroidism, medications and polycystic ovary syndrome.