Objective:To collect information on the seasonal activity of filarial vector around foothills of Susunia of West Bengal, India.Methods: Indoor-resting mosquitoes were collected from the human habitations of16 villages. Collected mosquitoes were identified and examined for different parameters following standard methods recommended by World Health Organization and pioneer workers.Results: Overall man hour density, infection rate, infectivity rate, human blood index and daily mortality rate of the vector were assessed as10.54%, 6.31%, 1.38%, 77.33% and13.00%, respectively, which were12.17%, 8.63%, 2.26%, 100.00% and17.00%, respectively in the summer season. Average load of microfilaria,1st stage,2nd stage and3rd stage larvae ofWuchereria bancrofti in infected vectors were10.02, 7.50, 5.56 and4.68, respectively, which were11.58, 9.90, 6.27and5.44, respectively in summer. Among the searched shelters 63.37%, 8.16% and2.08% were found to be invaded by any vector, infected vector and infective vector, respectively, which were68.75%,12.76% and3.91%, respectively in summer.Conclusions: Different indices related to the vector were much higher in summer, which indicates that, summer is the most favorable season for transmission of lymphatic filariasis in the study area. Available data will help to formulate an effective vector control measure.