No further reports of associated X-linked hypogammaglobulinemia and isolated growth hormone deficiency have appeared in the literature since the description of the first affected family, two brothers and two maternal uncles, by Fleisher et al. in 1980. We report here a 13-year-old boy with X-linked agammaglobulinemia and isolated growth hormone deficiency, also probably inherited as an X-linked trait. The height of an older agammaglobulinemic brother who died at 6 years of age was below the third percentile.