Zinc sulfadiazine is a new compound which is effective in vitro and in vivo against Pseudomonas aeruginosa infections in burned mice and rats. It contains an important body constituent, zinc, and appears to expedite wound healing, diminish weight loss after infected burns and improve food intake. Like silver sulfadiazine, it prevents the postburn changes in plasma proteins. After topical application, the uptake of the radioactively labeled zinc is significant in the zone of injury and negligible in organs and body fluids. The binding to deoxyribonucleic acid by zinc is similar to, but less than, that by silver. The data indicate that zinc sulfadiazine may be a valuable addition to the therapeutic armamentarium for the control of burn wound sepsis.