Ethanol-utilizing bacterial strain S543 which was isolated from a soil sample and identified as Pseudomonas fluorescens co-produced a plant hormane indole-3-acetic acid and antifungal antibiotics (pyoluteroin and 2,4-diacetylphloroglueinol) at cosiderable amounts when grown on ethanol as a sole carbon source. These bioactive compounds were never produced when the bacteria was grown on any other carbon source than ethanol. Inorganic phosphate or sodium chloride was inhibitory on the production of both the hormone and antibiotics while magnesium ion was stimulatory. Productions of indole-3-acetic acid and pyoluteorin by strain S543 grown in the 1.5% ethanol medium with supplimented with 0.1% L-tryptophan were 30 mg/ml and 45 mg/ml, respectively, both being much more than those in the literatures. It was considered that strain S543 was very profitable for use as a biocontrol agent because of the co-production and the high yields of both the metabolites.