Objective To study the effect of oral administration of activated charcoal and mannitol on removing toxicant after acute organophosphorus pesticide poisoning (AOPP). Method A total of 41 patients with severe AOPP were randomly divided into experiment group (activated charcoal used as adsorbent and mannitol used as cathartics, n =21)and control group (without adsorbent and cathartics, n = 20). Patients of both groups received routine treatment for AOPP after admission to hospital. The differences in duration of atropinization, the length of hospitalization and the success rate of treatment were compared between two groups. Results There were significant differences in duration of atropinization, the success rate of treatment and hospitalization time between the two groups. Conclusions The combination of activated charcoal and mannitol is more effective than the conventional gastric lavage on removal of organophosphorus pesticides from G-I tract, shorting the duration of atropinization time and hospital stays, and enhancing the success rate of rescue as well as improving the outcome of patients after organophosphorus pesticide poisoning.