Acute organophosphorus pesticide poisoning is widespread and the most common in many developing countries, including Nepal. Through the inhibition of acetylcholinesterase, organophosphorus poisoning is characterised by the clinical picture of acute cholinergic crisis. Many researchers have shown increased levels of liver enzymes and decreased levels of serum cholinesterase in organophosphorus poisoning, however, very little work has been done in Nepal that studies the correlation between serum cholinesterase and liver enzymes in organophosphorus poisoning. The aim of the study is to find out the mean cholinesterase level among organophosphorus poisoning patients visiting the Emergency Department in a tertiary care centre. This was a descriptive cross-sectional study done among 94 organophosphate poisoning cases visiting the emergency department of a tertiary care centre from August 2021 to August 2022 after obtaining approval from the Institutional Review Committee (Reference number: 04102021/06). Convenience sampling was done. Blood workups were done for cholinesterase and liver function tests. Point estimate and 90% Confidence Interval were calculated. The mean cholinesterase level among organophosphorus poisoning patients was 1978.82±1878.22 (1660.17-2297.47, 90% Confidence Interval). The mean cholinesterase level among organophosphorus poisoning patients was similar when compared to other studies done in similar settings. cholinesterases; liver function tests; organophosphorus poisoning.