The parasitic nematodes Wuchereria bancrofti, causes a dreadful disease in humans known as lymphatic filariasis, which afflicts more than 250 million people in tropical countries. Twelve districts with about 20 million people are endemic out of 64 districts in Bangladesh affecting more on Northern districts. This study was done in the Nilphamari, Kisorgonj and Sayedpur Thana under Nilphamari district, which is the most endemic for filariasis. In the present study, nineteen unions were investigated. Average 1.34% people were infected with filariasis (0.87% male and 1.81% female) out of 2,32,005 populations in those area. The highest percentage of infected unions was Alam Biditor (1.35%) under Kisorgonj Thana and lowest infected unions was Khatamadhupur (0.21%) under Sayedpur Thana. Among the affected people, 69.48% were poor, 28.88% were middle class and 1.63% was rich. The age group, 26-45 years, showed the highest rate (53.07%) of infection and the age group, 6-15 years, showed the lowest rate (1.92%) of infection. The relationships between infection status of male and female were statistically significant.