Abstract Objective: To determine if the bone mineral density loss seen after spinal cord injury (SCI) is reversed by a walking program using the Parastep® 1 system. Design: Before-after trial. Setting: Human SCI applied research laboratory. Participants: Thirteen men and 3 women with thoracic motor- and sensory-complete SCI, mean age 28.8yrs, mean duration postinjury 3.8yrs. Intervention: Thirty-two functional neuromuscular stimulation (FNS) ambulation training sessions using a commercially available system (Parastep® 1). This system consists of a microprocessor-controlled stimulator and a modified walking frame with finger-operated switches that permit the user to control the stimulation parameters and activate the stepping. Outcome Measure: Bone mineral density at the femoral head, neck, and Ward's triangle measured using a Lunar®DP3 dual-photon densitometer. Results: No significant change in bone mineral density was found using repeated measures analyses of variance. Conclusions: Axial loading combined with muscle stimulation and resistive exercise does not result in significant changes in bone mineral density in persons with complete paraplegia.