Becker’s melanosis is a fairly common disorder found in all races. Rarely, Becker’s melanosis may be associated with hypoplasia or hyperplasia of underlying structures. With the exception of one patient with foot enlargement, most reported associated features have been hypoplastic. We report one case with extensive Becker’s melanosis accompanied by ipsilateral lower limb hyperplasia and pectus excavatum. In the literature, this is the second case associated with hyperplasia of underlying structure and the first case associated with pectus excavatum.