Rathke's cleft cysts are cystic sellar and suprasellar lesions, characteristically lined by a single layer of ciliated cuboidal or columnar epithelium. In contrast, craniopharyngiomass, which are also cystic sellar and suprasellar lesions, are characteristically lined by stratified squamous epithelium with keratinization on a layer of connective tissue. The usual management recommended for Rathke's cleft cysts is simple surgical drainage with partial excision of the cyst wall. Recurrences of these cysts reportedly have been very rare. This retrospective study presents the details of 12 patients (6 females; median age 30 yr, range 21-58 yr) with Rathke's cleft cyst, referred to our department over a 15-yr period (1981-1996), an unusual feature being the recurrence of 4 (33%) of these lesions. Clinical, endocrine, radiological, surgical (10 transsphenoidal; 2 transcranial), and pathological details were recorded. Nine out of 12 patients (75%) were symptomatic; visual symptoms were the commonest, and 8 had visual field defects. The median duration of symptoms was 12 months (range 3-24 months). Three patients (25%) had panhypopituitarism, 2 of whom also had diabetes insipidus (17%). The cysts varied in size from 6 mm to 50 mm, 1 being entirely suprasellar. There were no pathognomonic clinical or radiological features to differentiate them from other pituitary lesions, although the presence of diabetes insipidus in 2 patients suggested that the lesion was not a pituitary adenoma. A definite histological diagnosis was possible in 8 patients; in 4, the diagnosis was presumptive. The median duration of follow-up was 30 months (1-168 months). Four patients (33%) showed reexpansion at 3, 6, 48, and 48 months after initial surgery, 3 of whom were symptomatic and required repeat surgery. Two of these patients were given postoperative external beam pituitary radiotherapy. Apparent recurrence of Rathke's cleft cysts after initially successful surgery in our series was higher than suggested by previous reports, and thus, long-term follow-up with pituitary imaging and neuroophthalmological assessment is essential. There are no specific characteristics of the cyst that predict recurrence. Ideal management of these cysts is unclear, but aspiration, followed by extensive excision of the cyst wall when possible, seems to be the best initial option. For recurrent symptomatic tumors, surgical resection is the treatment of choice. Considering the high recurrence rate with residual structural and functional dysfunction, the role of radiotherapy in preventing recurrence of these cysts needs careful evaluation with a larger study with a longer follow-up period.