The dichloromethane extract of red rose petals afforded 2-oxopomolic acid (1) and sitosterol by silica gel chromatography. The structure of 1 was elucidated by extensive 1D and 2D NMR spectroscopy. Antimicrobial tests on 1 indicated that it is active against the fungi C. albicans and T. mentagrophytes. It was also found to be slightly active against the bacteria E. coli, P. aeruginosa, and S. aureus. It was inactive against B. subtilis and A. niger.