Organophosphates (OPs) are most widely used group of pesticides in the world that are employed in agriculture and militarian sites since the 1940s. These pesticides affect central and peripheral nervous system by inhibiting acetylcholinesterase. OPs have toxic effects on respiratory, gastrointestinal, circulatory, immune, endocrine and nervous systems. Acute or chronic exposure to OPs is associated with cancer, reproductive problems, birth defects and developmental anomalies. Widespread exposure to OPs makes adequate medical tratment urgent. General medical therapy consists of a combination of acetylcholinesterase inhibitors, oximes and atropine. A new approach in treatment of organophosphate poisoning is usage of human acetylcholinesterases as a bioscavenger.