PIP: Recent work suggests that short-chain aliphatic acids in vaginal secretions may play a role of pheromones in primates, including humans. An experiment was conducted with 3 women to determmine the odor composition of vaginal secretions before and after coitus. Prior to coitus they refrained from sexual activities for 48 hours, did not use a vaginal douche for 7 days, did not bathe or shower for 24 hours, and did not use vaginal hygiene preparations for 72 hours. Samples of vaginal secretions were taken at 9:00 A.M., 1:00 P.M., and 5:00 P.M. on the day before coitus. After coitus at 7:00 A.M., samples were again taken from each subject at the same hours as before. A condom was used in 1 coitus to prevent male secretions and seminal fluids from entering vaginal secretions. The GC/sensory assay (odorogram) was used and odor description notes made. The survey indicated that 13 odorous compounds occurred regularly. It was noted that components with acidic odor tended to appear at lower retention rates in postcoital samples. The chemistry of these compounds was not investigated. It is concluded that differences exist in the odors of pre- and postcoital vaginal secretions. The biological relevance of these differences was unresolved. The question of the pheromonic significance of vaginal odors in humans remains undetermined.