We reviewed the clinical course in 43 patients from eight medical centers who were given the diagnosis of chronic mucocutaneous candidiasis, a rare disorder of unknown cause that may occur in childhood. Recurrent or severe infections with organisms other than Candida were seen in 80% of the patients. There were nine cases of septicemia. Seven patients have died; six of these deaths were directly related to non-Candida infectious complications. Endocrine dysfunction, including Addison disease (11 patients) and hypothyroidism (9 patients), was seen in 19 of 43 patients. Immunologic studies failed to reveal a consistent abnormality, although two of five patients with reversed T4/T8 ratios are among those who have died. Ketoconazole was effective in controlling symptoms of candidiasis in most patients. The findings from this study indicate that non-Candida infections cause serious morbidity and may result in death in patients with chronic mucocutaneous candidiasis.