The efficacy of clay or alcoholate as decontaminants in pigs percutaneously poisoned with 6 LD50 of O-ethyl S-2-diisopropylaminoethyl methylphosphonothioate (VX) and 3 LD50 of 1,2,2-trimethylpropyl methylphosphonofluoridate (soman) nerve gases was tested. It was assessed by the time of onset of the first signs of poisoning and death, as well as by the activity of blood cholinesterase (ChE). No toxic signs or fatalities were observed in decontaminated pigs, regardless of the decontaminant used. In VX poisoning up to 240 min. both decontaminants kept ChE values at normal level. Twenty four hours later, ChE activity in pigs decontaminated with clay was 71%, significantly higher than in pigs decontaminated with alcoholate (49%). In soman poisoning the activity in control group was maintained at almost normal level up to 60 min, followed by rapid fall to 58%. Further readings were impossible due to the death of all animals. No significant difference between decontaminants could be noticed throughout the observation of 24 hr. The values were kept between 80 and 100%, with the trend of rising after 120 min.