The clinical and pathologic findings in two white male children with repeated infections, including lymphadenitis, aphthous stomatitis, enteritis, pneumonitis, osteomyelities, etc. are described. Tissue removed at laparotomy in one patient, and at necropsy in the other, showed infiltration of organs by lipid histiocytes containing yellow-brown pigment. Although the histochemical properties of the cells show similarities to the lipid histiocytes of Niemann-Pick disease, the condition described is considered to differ from other forms of lipid histiocytosis, as well as from other conditions producing susceptibility to infection. Concentrations of gamma-globulin in the serum of one of the patients were elevated, but whether the globulin is functionally effective is not known. The onset of symptoms in early infancy suggests that the disorder is genetically determined rather than acquired, but no evidence of familial occurrence has been obtained.