A 6 mg./kg. daily dose of levamisole was given during three days to ten carriers of microfilarias Wuchereria bancrofti in Tahiti. No action against adult worms was noticed. The immediate microfilaricid action was at least equivalent to the action of DEC. However the decrease of microfilaremia was not so long with levamisole than with DEC given to a lower dose. Lastly the amount of reactions after a treatment by levamisole is notable.