Abstract. Five family members over 3 generations had isolated functional pituitary adenomas diagnosed. In four cases acromegaly was diagnosed, and in the fifth galactorrhoea from prolactin excess was the presenting feature. A prominent feature of the affected members tumours were histological finding of either atypical mixed cell or undifferentiated cell type. Given the low incidence of acromegaly and the demonstration of vertical transmission over 3 generations it is suggested this family represents an inherited pituitary syndrome, distinct from Multiple Endocrine Neoplasia (MEN) type 1.