Conventional X-rays are rarely helpful in diagnosing lymphatic filarial infection, except in the case of tropical eosinophilia where the picture can be variable but characteristically includes interstitial thickening and diffuse nodular mottling in the lung fields. Ultrasound examination of the lymphatics (especially scrotal lymphatics in men, and the breast and retro-peritoneal lymphatics in women) can reveal rapidly moving ("dancing") adult worms (see 'Animated documentation of the filaria dance sign (FDS) in bancroftian filariasis' in Filaria Journal), and lymphoscintigraphy, though not diagnostic of filarial infection, can identify lymphatic functional and gross anatomical abnormalities.

In situations of lymphadenopathy with or without accompanying inflammation of the nodes or lymphatic vessels, biopsy can often detect adult worms, but this approach is rarely used as a diagnostic procedure.