A latex agglutination inhibition test was developed for detection of cholera toxin. Cell-free extract was at first neutralized with anti-cholera toxin, then the latex particles having coupled covalently with cholera toxin were added to detect the presence of cholera toxin. The test was performed on glass slide. Using this method, the concentration of cholera toxin as low as 1.25 micrograms/ml can be detected within 2 minutes at room temperature. Procedure for covalent conjugation of cholera toxin to polystyrene latex particles was simple and the conjugation preparations were stable at 4 degrees C for at least 6 months.