The activity of chlorquinaldol, a derivative of hydroxy-8-quinolein used for local antisepsy, was studied against Neisseria gonorrhoeae and Chlamydia trachomatis. The weak solubility of the product and the special growth conditions of the organisms made an adaptation of the AFNOR norm necessary. For 0.1 to 0.2% (W/V) chlorquinaldol concentrations, a reduction of about 10(4) organisms was obtained after 60 minutes for N. gonorrhoeae and C. trachomatis. However, for technical problems, the concentrations tested were 10 to 100 times lower than the doses usually recommended for this antiseptic.