Blood serum FSH, LH, prolactin and testosterone as well as urinary excretion of 17KS and 17-OHCS were determined in 8 patients with chromophobe pituitary adenomas treated by transphenoidal microsurgical removal or craniotomy with or without subsequent telecobalt therapy. It was found te disease tends to recur in the majority of patients despite the type of therapy. Recurrence is accompanied by gonadotropins hyposecretion, increase in prolactin secretion, secretory disorders in the gonads and adrenals; an increase in prolactin secretion is proportional to the intensity of the compression symptoms. Bromocriptine in a daily doses ranging from 5.0 to 7.5 mg decreases prolactin levels in the recurrent chromophobe pituitary adenomas and does not affect their proliferation.