The BŻ-4 Żuk was based on a single main three-blade rotor powered by an indigenous Narkiewicz WN-4 piston engine in a fuselage made of a steel frame, behind a cabin section. It had an open frame rear boom structure and a fixed four-wheel undercarriage. Main rotor was atypical, for it had a smaller upper steering rotor and was fitted with an automatic stabilization system, of the Hiller principle. The cabin had four doors with two front seats and a rear bench. There were two fuel tanks, 220 l in total.