Constitutional (familial) precocious puberty in the male is a rare entity; a review of the literature reveals only nine reports on this condition. Stone,1 in 1852, reported the first case, a 4-year-old boy whose father had also been affected. It was not mentioned again until 1922, when Reuben and Manning2 reported a similar case. Orel,3 in 1928, reported its occurrence in two additional families. Rush and his co-workers, in 1937,4 reported on a family in which premature development had been noted in four generations. Sigrist,5 in 1940, reported on an additional family. Engstrom and Munson, in 1951,6 described still another family, with the father and two sons affected. In 1952, Jacobsen and Macklin reported a single family in which 27 members over a span of five generations had been affected,7 and in the same year, Walker8 reported a family with father, son,