52 vaginal lavages from 33 chimpanzees (Pan troglodytes) of various age classes and reproductive states were examined for volatile fatty acid content by means of liquid gas chromatography. Features of the acid complex in chimpanzee vaginal secretions distinguish these apes from other anthropoids investigated and may constitute and odor signal that identifies chimpanzees. It was not possible to discriminate between the most and least fertile stages of the estrous cycle or among individuals on the basis of acid characteristics. If volatile fatty acids in chimpanzee vaginal secretions are components of a sexual pheromone or pheromones, it is more likely that they are immediate releasers of attraction than of sexual behavior.