This two-beam terahertz FMCW walk-through body scanner can measure the front side and the back side of a pedestrian walking at 4 km/h with 3D renderings. In a novel implementation, two pairs of illumination and detection beams measure both sides in a single pass. The lateral resolution of both beams was measured at 11.6 mm, which was close to the theoretical value. Telecentric performance was maintained for both beams. The range profile of the FMCW was evaluated from 10 ms to 10 μs sweep with no change in depth resolution. A method to reduce the data processing time and 3-D analysis area extraction was presented.