Suppression of cell-mediated immunity (CMI) follows a major thermal injury and is associated with an increased incidence of serious infections. Adult female CF-1 mice received a 20% full-thickness steam burn and were then treated with various topical antimicrobial creams in an attempt to alter the course of postburn immunosuppression. Topical agents included cerium nitrate (CE), silver sulfadiazine (SSD), mafenide (SML), silver nitrate (AG), and a mixture of CE and SSD (CE-SSD). CMI was determined in vivo by measuring ear swelling in response to 2,4-dinitrofluorobenzene (DNFB) challenge in previously sensitized mice. The usual nadir in CMI (ear swelling) when mice were sensitized at day 14 postburn did not occur in burned mice treated with CE or CE-SSD, AG was only modestly effective, and SML or SSD failed to restore CMI. These studies suggest that topical CE may have potential as an immunomodulator in the treatment of burns.