We report 5 clinical cases of primary hypothyroidism or premixedema with associated pituitary lesion. Before treatment was started with L-thyroixine (L-T4) pituitary hormones were examined and an X-ray of the silla turca as well as a CT scan of the hypophysis (CTH) was done. Once supplementation treatment was started hormone levels normalized. In three out of the 5 cases, CT scan done after establishing therapy, showed empty silla turca. Therefore, me stress the importance of closely examining the pituitary gland in patients with untreated primary hypothyroidism.