Mice injected intravenously (IV) or subcutaneously (SC) with living Candida albicans developed subsequently delayed-type hypersensitivity (DTH) which was measured in vivo by the footpad test after injection of 10(6) heat killed C. albicans (HKC.a.). Compared to systemic injections, SC immunizations with living C.a. gave higher levels of DTH, and lethality was absent. Subcutaneous injections of hundred time more doses of HKC.a. were also able to produce in normal mice a DTH reaction elicited with HKC.a. or with C.a. soluble extracts, but not with candidine. Intraperitoneal injections of varying doses of HKC.a. or subcutaneous injections of varying doses of C.a. soluble extracts failed to produce significant DTH. High levels of sensitization can be induced by using cyclophosphamide or BCG or both pretreatment before immunization, which seems to indicate immunomodulating factors for induction or expression of DTH in normal mice after injections of HKC.a. Kinetics of the local reaction elicited with HKC.a. fulfull usual criteria of DTH in actively immunized mice after CY pretreatment or not, and in passively immunized mice after systemic or local transfer of spleen cells from actively immune donors. Serum from same group of donors was unable to transfer DTH.