The clinical examination of residual limb complications is usually subjective and may lead to inappropriate, expensive adjustments or replacement of the prosthesis. Plain films and xeroradiography only provide static images of the residual limb and socket. The purpose of this pilot study was to develop a videofluoroscopic technique to evaluate dynamic residual limb-socket relationships during gait. Sixteen videofluoroscopic studies were performed in subjects with transtibial amputation. Anteroposterior (A-P) and lateral views were obtained. The wide view field was better than the coned view. The optimal settings were found to be in the 80 to 110 kV range during manual setting (mean values: 86.3 kV in A-P view, and 88.9 kV in lateral view). The following information was obtained: A-P residual limb motion, piston action, rolling of soft tissues, and dynamic relationships of various pressure-sensitive and pressure-tolerant parts of the residual limb with the inner socket. We consider videofluoroscopy to be a potentially valuable diagnostic procedure for evaluating difficult prosthetic fitting problems and residual limb complications, and providing a better understanding of the residual limb-socket interface during different phases of the gait cycle.