There was a resurgence of malaria in India following resistance of the vector to DDT, Lindane and malathion and an alternative insecticide was sought to meet emergency cases. A large field trail was carried out to determine the impact of a single application of fenitrothion at 2 g/m2 in a triple resistant area of Gujarat State, India. The results showed that the residual effect lasted for over three months and that fumigant action lasted for 71 days after spraying, bringing about a decrease in malaria prevalence.