The ability of the oxime HS-6 [1-(4-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium)-2-oxa-propane dichloride] to reactive in vitro the enzyme acetylcholinesterase inhibited by the nerve agent sarin [O-isopropylmethylfluorophosphonate] was evaluated. The reactivators 2-PAM [2-hydroxyiminomethyl-1-methylpyridinium chloride], toxogonin [1,3-bis(4-hydroxyiminomethylpyridinium)-2-oxa-propane dichloride] and H-oxime HI-6 [1-(2-hydroxyiminomethylpyridinium)-3-(4-carbamoylpyridinium)-2-oxa-propane dichloride] were chosen for comparison. The oxime HS-6 was an effective reactivator of sarin-inhibited AChE. It is not as effective as the H-oxime HI-6, but it is better than 2-PAM and obidoxime.