Previous studies have shown cost er ectiveness and quality-of-life benefit of pneumatic compression therapy (PCT) for lymphedema (LE). Insurers, such as the Centers for Medicare/Medicaid (CMS), however, desire visual proof that PCT moves lymph. Near-infrared fluorescence lymphatic imaging (NIRFLI) was used to visualize lymphatic anatomy and function in four subjects with primary and cancer treatment-related LE of the lower extremities before, during, and after PCT. Optically transparent and windowed PCT garments allowed visualization of lymph movement during single, 1 h PCT treatment sessions. Visualization revealed significant extravascular and lymphatic vascular movement of intradermally injected dye in all subjects. In one subject with sufficient patent lymphatic vessels to allow quantification of lymph pumping velocities and frequencies, these values were significantly increased during and after PCT as compared to pre-treatment values. Lymphatic contractile activity in patent lymphatic vessels occurred in concert with the sequential cycling of PCT. Direct visualization revealed increased lymphatic function, during and after PCT therapy, in all LE-affected extremities. Further studies are warranted to assess the erects of PCT pressure and sequences on lymph uptake and movement.