The delayed type hypersensitivity response to human serum albumin (HSA) of rats infected intraperitoneally with 10(7) viable C. neoformans cells, and 7 days after, immunized with human serum albumin was significantly diminished (p less than 0.05) when compared with the response observed in rats immunized with human serum albumin and non infected. The spleen mononuclear cells from suppressed rats transferred to normal syngeneic recipients of the same sex suppress the afferent phase of the response (p less than 0.02) suggesting that cells present in the spleen might be one of the responsible mechanisms for the suppression to non-related antigens in infected animals.