Organophosphorus compounds, especially nerve agents, inhibit enzyme acetylcholinesterase (AChE; EC 22.214.171.124) in an irreversible manner. Atropine plus an oxime reactivator are used as an effective treatment of organophosphate poisoning. In this work, we have evaluated reactivation potency of twenty reactivators of different chemical structures in reactivation of VX-inhibited AChE. Rat brain AChE homogenate was used as the appropriate source of the enzyme. According to our results, trimedoxime seems to be the most potent reactivator of VX-inhibited AChE at the concentration 10-3 M.