A study of protein characterization and recognition of the antigenic profile was accomplished in extracts of infective larvae (L3) from Wuchereria bancrofti. Two proteins of relative molecular weight of 49 and 55 kDa were recognized as antigenic in all extracts by the tested sera. The secretory/excretory antigen presented the largest number of recognized bands (105, 100, 76, 55, 49, 39 and 32 kDa) followed by the somatic antigen (100, 76, 55 and 49 kDa) when incubated with pools of sera from healthy individuals resident in endemic areas (normal endemics). Human sera and parasitized blood used to infect mosquitoes in order to obtain L3, were collected from microfilaraemic individuals living in a filariasis endemic area. From 792 persons screened with the thick smear technique, 87 (11%) were positive. No statistical significance was observed between genders. The group between 11 and 19 years of age presented higher percentage of infection (36.8%).