Eight adolescent patients, 4 boys and 4 girls with prolactin secreting pituitary adenomas have been studied. The first symptoms developed between the ages of 8 and 14 years. The main complaints were headache (7 cases), delay or failure of growth (6 cases) or of puberty (3 cases), and amenorrhoea with galactorrhoea (2 cases). The diagnosis could be made easily from the enlarged sella turcica and the high plasma prolactin levels. Anterior pituitary insufficiency is variable. Persistent hyperprolactinaemia after surgery may require treatment with bromocriptine.