Background & objectives: Disease burden due to lymphatic filariasis is disproportionately high despite mass drug administration with conventional drugs. Usage of herbal drugs in traditional medicine is quite well known but largely empirical. Hence the present study was designed to screen the in vitro antifilarial effect of four herbal plants on Brugia malayi. Methods: Motility of microfilariae of B. malayi after incubation for 48 h with aqueous/methanol extracts of Vitex negundo L. (roots), Butea monosperma L. (roots and leaves), Ricinus communis L. (leaves), and Aegle marmelos Corr. (leaves) was explored in the concentration range of 20 to 100 ng/ml for possible antifilarial effect by comparing with suitable solvent control.