A novel millimeter-wave portal for human body imaging is presented in this work. Its aim is to produce accurate geometric reconstruction of the human body torso and body-borne objects concealed under clothing with size as small as 1 cm. For this purpose, a multistatic Synthetic Radar Aperture (SAR) imaging system working in the 56-64 GHz frequency band has been designed and manufactured. A novel elliptic-parabolic reflector antenna design capable of providing wide illumination in azimuth and a very narrow beam in elevation is used, allowing the independent processing of narrowly illuminated slices of the human body. Fast and accurate SAR imaging techniques have been developed to recover the reflectivity of these slices from the acquired scattered field. Combining the reflectivity images of each slice provides a 3D reconstruction of the human body torso as well as any concealed objects. A first prototype of the mm-wave portal is presented in this contribution, together with several application examples which clearly show the system capability for detecting small objects placed on a mannequin emulating the human body torso.