A monoclonal antibody-based antigen detection system was used to detect the levels of circulating antigen in filarial patients before and after treatment with DEC and in normal individuals living in an area endemic for W.bancrofti infection in Chennai, India. The present study was to show the use of this assay as a means of efficient screening for filariasis in an endemic area where blood was absorbed onto the filter paper by finger prick during day time. The results of the antigen levels collected onto filter strips correlated with their corresponding plasma antigen levels (r=0.83). In microfilaraemics, DEC treatment did not alter the levels of circulating antigens upto a period of one month. We conclude that this monoclonal antibody based ELISA using filter strips may be used in daytime and can replace the existing routine night blood survey.