Objective:To isolate the larvicidal component from the fruits ofPiper longum (P. longum) against the filariasis vector,Culex quinquefasciatus (C. quinquefasciatus).Methods: Pulverized fruits ofP. longum were subjected to soxhlet extraction using series of organic solvents of increasing polarity. All the solvent extracts were verified for their larvicidal efficacy against 4th instar larvae ofC. quinquefasciatus employing standardWHOprocedure. Bioassay-guided fractionation through column chromatography lead to the isolation of a bioactive amide, pipyahyine from the petroleum ether extract.Results: Petroleum ether extract was found to be the most active fraction among all the extracts tested with LC50 andLC90being1.03 and2.04ppm respectively. Whereas, pipyahyine, an isolated component of the same fraction was found to be even more effective than the parent extract in terms ofLC50being0.58 and1.88 ppm respectively. Conclusions: From the results, it is evident thatP. longum can be considered as a powerful arsenal for the control of mosquito population.