The acute toxicity and the effect of steam distillate obtained from several plant mixtures (G-3) on the reactivation of brain, lung, and blood acetylcholinesterase (AChE) activity, and recovery from other toxic symptoms following intoxication by organophosphate pesticides were investigated in mice and mudfish. Administration of G-3 $(50{sim}100;ml/kg,;i.p.)$ immediately or 30 min prior to Diazinon or Sumithion treatments, respectively, resulted in a significant reactivation of AChE activity in brain, lung, and blood, their potencies being almost equipotent to those of 2-PAM, one of well-known antidotes. G-3 itself exhibited almost no acute toxicity even at the highest dose employed, and without effect on the inhibition of hepatic drug metabolism function following organophosphate administrations. G-3 showed a significant diminution of the death rate in mudfish as well as in mice intoxicated by Diazinon.