The aim of the study was to estimate serum amylase and serum cholinesterase levels in patients of acute OP poisoning and to correlate serum amylase levels with serum cholinesterase and outcome in term of mortality in same patients. Material and Methods: A prospective observational study was conducted in 106 clinically proven cases of OP poisoning attending the Emergency Department of Sir Takhtsinhji General Hospital, Bhavnagar. Serum amylase and Cholinesterase were measured on fully auto analyzer ILab at the time of admission. Patients were followed up for final outcome. Results: Serum cholinesterase levels were decreased in all the three groups. Serum amylase was significantly elevated in group III when compared to group I and II. Correlation between serum cholinesterase levels and serum amylase showed significant negative correlation. Mean value of serum cholinesterase and serum amylase at the time of admission in survivor were 1265±866.5 and 146±68.24 respectively while in non-survivor 756.4±741 and 417±138.6 respectively. Conclusion: Acute OP poisoning is associated with increased serum amylase levels and decreased serum ChE levels. Serum cholinesterase inhibition & lt;10% and hyper-amylasemia & gt;300 U/L has been associated with high degree of mortality. Serum amylase estimation can be used as a prognostic indicator along with the serum cholinesterase activity in assessing severity of OP poisoning. Further studies with estimation of isoenzymes of amylase and correlation with clinical severity in larger population is necessary to know the type of hyperamylasemia and its clinical significance in acute OP poisoning

Keywords : Amylase, Cholinesterase, Organophosphorus poisoning.