A 7 1/2-year-old boy with chronic renal failure (CRF) experienced transient central isosexual precocious puberty. Simultaneously, he demonstrated hyperprolactinemia with galactorrhea and apparent secondary or tertiary hypothyroidism. These findings could have been a consequence of an unexplained hypothalamic dysregulation. During this period, marked linear growth ensued (8.7 cm during nine months) associated with rapid bone age advancement (four years during a 21-month period). Whereas most boys with CRF demonstrate delayed pubertal development and suppressed linear growth, our patient's transient condition demonstrated that both growth and puberty can occur in the presence of uremia.