Disclosed is a new portable vehicle-mounted gun rack, for use in vehicles having a floor with at least one generally horizontal planar portion situated generally in front of a bench seat having an upwardly projecting backrest, for supporting a plurality of long-barreled firearms for safe transport whereby the firearms are readily accessible and no modification is required to the vehicle. The portable vehicle-mounted gun rack comprises a lower floor engagable support structure for receiving a plurality of guns by the muzzle. The lower support structure comprises an elongated block having a plurality of spaced apart upwardly opening gun muzzle sockets formed therein whereby the plurality of guns may be partially supported by their downwardly angled muzzles. An upper seat backrest engagable support structure for receiving the plurality of guns by the butt is also included. The upper support structure comprises an elongated block having a plurality of spaced apart front facing lateral gun butt slots formed therein whereby the plurality of guns may be supported by their upwardly angled butts. The upper support structure has hanger brackets attached to the back face of the block whereby the upper support may be hooked over the top front edge of the vehicle seat backrest. The upper support structure is cooperably aligned with the lower support structure so the combined support structures in combination with the vehicle floor and seat backrest define a rack wherein the guns are firmly held in bridging fashion between the upper and lower support structures.