D51 connects A3 motorway Nova Gradiška interchange to Nova Gradiška and Požega. The road forms two junctions to D38 state road, one in Brestovac, where D38 branches off to Pakrac, and another further east, in Požega, where D38 branches off to Pleternica. Between those two junctions D51 and D38 are concurrent. The eastern terminus of the road is near Gradište, at a junction to D53 state road to Našice (to the north) and Slavonski Brod (to the south). The road is long.