Determinations of plasma cholesterol, HDL-cholesterol, triglycerides, total proteins, bilirubin, aspartate transaminases (AST), glucose, iron and total iron binding capacity were evaluated after 15 and 90 days of intraperitoneal infection with 5 x 10(6) virulent yeasts of Paracoccidioides brasiliensis Pb 18 isolate in resistant (A/J) and susceptible (B10.A) mice. Significant differences between control and infected groups were seen: an increase of triglycerides and total proteins for both strains, a decrease of glucose and HDL-cholesterol in B10.A mice and of iron in both strains, while AST, bilirubin and TIBC increased only in B10.A mice. While glucose, AST, bilirubin and TIBC were strongly modified in susceptible mice, no differences were seen in the resistant infected group, thus confirming the usefulness of biochemical parameters as an index of infection severity, as well as of recovery.