Thirty-eight patients underwent transsphenoidal microsurgical treatment of non-neoplastic intrasellar cysts: 36 had cyst drainage and biopsy of the cyst wall, and in two the cyst was totally removed. Surgical morbidity was 8%. The mean follow-up time was 46.3 months; 100% patient follow-up evaluation was achieved. Sixteen female patients (mean age 24.6 years) had pars intermedia cysts: 88% had menstrual irregularities, 63% had galactorrhea, 31% had headache, and 56% had hyperprolactinemia. Within these groups, menstrual cycles returned in 86%, galactorrhea ceased in 90%, headaches resolved in 80%, and serum prolactin levels were restored to normal in 66%. Eight females and three males had Rathke's cleft cysts (mean age 34.0 years): of these 11 patients, 91% had headaches and 18% had hyperprolactinemia; of the eight females, 63% had amenorrhea and 63% had galactorrhea. Within these groups, serum prolactin levels normalized in 50%, and 80% noted reduced headache. Of the females, 80% had return of menses and 50% noted cessation of galactorrhea. Six males and two females had arachnoid cysts (mean age 42.2 years): 50% had headaches; 50% were asymptomatic. Preoperatively, 50% of these patients had hypothyroidism and 25% had adrenal hypofunction. Postoperatively, 75% of patients with headache noted improvement, and 33% of patients with abnormal thyroid function had normal function. Adrenal function did not improve. Three patients had an intrasellar cysticercosis cyst, epidermoid cyst, and postoperative cyst, respectively. All had evidence of partial hypopituitarism; none improved postoperatively. The results indicate that different types of pituitary cysts produce different clinical syndromes, and suggest that simple transsphenoidal drainage and partial removal of the cyst wall can provide safe and effective therapy.