The PWS-20 was a Polish single-engine high-wing 8 passenger airliner, built in the PWS factory and when it made its first flight in 1929 it became the first Polish-designed transport aircraft to fly.

[3] LOT had already ordered a batch of single-engine Fokker F.VIIa/1m aircraft from the Netherlands, and while the performance and flight characteristics of PWS-20 were similar to the Fokkers, LOT's focus was moving toward longer international routes, which required a larger aircraft, such as the tri-motored version of the F.VII, and the need for either single engine type was shrinking, and worse, with only two in service, the PWS-20 was a maintenance problem.

The constant chord wings had rounded wingtips and were built up around two wood spars, with plywood ribs and a doped linen covering.

Two additional passengers could be carried on folding seats and there was a toilet, as well as room for 220 kg (490 lb) of baggage in two compartments.

The PWS-20 was powered with a 450 hp (340 kW) (nominal) or 487 hp (363 kW) (take-off power) Lorraine-Dietrich LD 12Eb W12 engine produced under licence by the Polish Skoda Works, driving a 3.2 m (10 ft) diameter two-blade fixed pitch metal propeller.

Initially this was formed from two vees, attached to the lower fuselage longerons and to each other with a spreader bar, with a wheelbase of 2.5 m (8 ft 2 in), this was replaced by individual legs, with a vee connected to the fuselage, and a vertical strut connected to the upper longeron, through one of the wing struts, with a wider 3.54 m (11.6 ft) wheelbase.