The possible interference of vaginal lubricants in culture diagnosis of gonorrhea was investigated by studying in vitro effect of selected lubricants on Neisseria gonorrhoeae. Two lubricants widely used in family planning and other clinics were demonstrated to have a bactericidal effect on N. gonorrhoeae when tested with more than one method. Gonococci were killed on contact with Lubrifoam, even at a 10 per cent concentration, and an exposure time as short as one minute was sufficient to inhibit the growth on chocolate agar medium. The K-Y jelly showed less inhibitory effect than Lubrifoam. These findings suggest that certain vaginal lubricants have bactericidal effects and their presence can inhibit the growth of Neisseria gonorrhoeae.