In four cases of chronic mucocutaneous candidiasis (CMCC) enhanced antibody production against candida antigen was detected in association iwth depressed cellular immunity. These patients showed extremely high agglutinin titre to candida antigen, while they were unable to mount delayed hypersensitivity reactions to candida antigen, tuberculin-purified protein derivative (PPD) or to dinitrochlorobenzene (DNCB). They also showed prolonged survival of skin homografts. There was no correlation between migration inhibitory factor (MIF) production and blast transformation in response to candida antigen.