Exposure of expatriates to the infective larvae of Wuchereria bancrofti can result in the early development of signs of lymphatic obstruction. The findings on the clinical presentation of expatriates are distinct from the chronic pathological findings seen among the native population and are similar to the findings in experimentally infected persons. We report the case of a Peace Corps volunteer who developed acute lymphatic dysfunction within 3 months of arriving in an area that was endemic for filariasis. The diagnosis was established clinically and by demonstrating the presence of antibodies to recombinant proteins specific for patients with lymphatic filariasis. Lymphatic flow was markedly abnormal when assessed with use of 99mTc-lymphoscintigraphy. Treatment with diethylcarbamazine reversed both the physical and lymphoscintigraphic abnormalities.