Organophosphate esters have wide scope in insecticides, herbicides and plasticizers industries etc. Since the organophosphate compounds have been reported biologically active, therefore it is essential to study the organophosphates systematically at all the faces of reactions. Now the emerging concern is the effect of Organophosphate esters on the environment. Many organophosphates are potent nerve agents, functioning by inhibiting the action of acetylcholinesterase (AChE) in nerve cells. Organophosphate esters are one of the most common causes of poisoning worldwide, in agricultural areas. This study is very important in present scenario. For researchers it is essential to pay desirable attention to the effect of each factor, as the rate of reaction is influenced by a number of factors such as ionic strength, concentration, temperature, solvent and catalyst etc. This book provides the detailed kinetic study on the hydrolysis of these Organophosphate esters. This study should be useful to Environmental Scientists