Albendazole and diethylcarbamazine (DEC) are currently used in combination for annual mass treatment of lymphatic filariasis in all parts of the world except Africa. Although the drugs have been donated, the cost of such programs is very high and has proven to be a major impediment to the success of programs in many countries with limited financial resources. Data from albendazole treatment of other filarial infections and one study comparing single to multi-dose DEC/albendazole in lymphatic filariasis suggest that increased dose and/or frequency of albendazole dosing may be more effective in clearing microfilariae. In this study, 75 volunteers with microfilaremic Brugia malayi infection will be randomized to receive standard annual therapy (albendazole 400 mg + DEC 300 mg), annual therapy with increased dosing of albendazole (albendazole 800 mg + DEC 300 mg), or semiannual therapy with an increased albendazole dose (albendazole 800 mg + DEC 300 mg). Microfilarial levels will be followed every 6 months for 2 years to determine whether the higher dose, and/or the more frequent regimen, is more effective.