Mosquitoes transmit serious human diseases, causing millions of deaths every year and the development of resistance to chemical insecticides resulting in rebounding vectorial capacity. Plants may be alternative sources of mosquito control agents. The present study assessed the role of larvicidal efficacy of different solvent flower extract of Cassia fistula (C. fistula) against Culex tritaeniorhynchus (Cx. tritaeniorhynchus) Aedes albopictus (Ae. albopictus) and Anopheles subpictus (An. subpictus). Twenty five early third instar larvae of Cx. tritaeniorhynchus, Ae. albopictus and An. subpictus were exposed to various concentrations and were assayed in the laboratory. The larval mortality was observed after 24 h of treatment. Among three solvent extracts tested the maximum efficacy was observed in the methanol extract and the LC50 and LC90values of C. fistula flower against early third instar of Cx. tritaeniorhynchus, Ae. albopictus and An. subpictus were 136.59, 118.64, 96.51 ppm and 243.67, 231.79, 174.39 ppm, respectively. No mortality was observed in controls. The chi-square values were significant at p < 0.05 level. From the results it can be concluded the crude extract of C. fistula flower was an excellent potential for controlling Cx. tritaeniorhynchus, Ae. albopictus and An. subpictus mosquito larvae.