Mice ingesting a standard rodent diet supplemented with polybrominated biphenyls (PBBs) were more susceptible to chlorinated hydrocarbon solvent-induced renal and hepatic damage, as well as the lethal effects of CHCl3 and CCl4, than were mice consuming control diet. As little as 0.025 ml/kg CHCl3 caused a significant increase in serum glutamic oxaloacetic transaminase (SGOT) and blood urea nitrogen (BUN) and a significant decrease in renal cortical slices accumulation of p-aminohippurate (PAH) in PBB-pretreated but not control mice. SGOT and serum glutamic pyruvate transaminase (SGPT) were greater in PBB-pretreated mice than in control mice after 0.125 and 0.005 ml/kg CCl4, respectively. Renal cortical PAH accumulation was greatly reduced in PBB-pretreated but not control mice aftter 0.125 ml/kg CCl4. The solvent-induced decrease in PAH accumulation was also greater in PBB-pretreated mice than in control mice following administration of 1.0 ml/kg trichloroethylene (TRI) and 0.15 ml/kg 1,1,2-trichloroethane (TCE).