Introduction: Organophosphates (OP) are used as insecticides in agricultural and domestic settings throughout the world. The mechanism of action is through the inhibition of the enzyme acetyl cholinesterase, leading to the accumulation of acetylcholine at cholinergic synapses. On a worldwide basis, pesticides are responsible for hundreds and thousands of cases of acute poisoning and many thousands of deaths each year. Objective: To evaluation of autopsy study of organo phosphorus poisoning in patients. Method: This retrospective type of study was conducted among 75 patients who fulfilled criteria from Forensic Medicine Dept. Sir Salimullah Medical College & Mitford Hospital, Dhaka, Bangladesh from July-2015 to July-2017. Results: During the study, 58% patients were male, which was 16% higher than female. 52.11% worked as an agriculture area/ farmer. Also, 76% people used organo phosphorus for suicide and 24% people used it accidentally. Conclusion: From our study we can conclude that, organophosphorus is a self-poisoning important clinical problem in developing world. Because of limited guide therapy, properly study is needed for seeking treatment which could help to reduce mortality and morbidity.