The SW-4 is powered by a single 335 kW (450 shp) (283 kW/380 shp max continuous rated) Rolls-Royce Model 250C20R/2 turboshaft engine, which drives the rotorcraft's three-blade main rotor and two-blade tail rotor. An alternative engine is provided in the form of the 460 kW (615 shp) Pratt & Whitney Canada PW200/9 turboshaft engine. The main rotor is fully articulated and the rotor blades on both the main and tail rotors are composed of composite materials. The SW-4 uses hydraulic flight controls, the rotorcraft has been promoted as possessing excellent flight controls, and can be flown in both day and night visual flight rules conditions.

The SW-4 is capable of transporting up to five people, including a pilot, in crashworthy seats; passengers are provided with a high level of external visibility and comfort, an optional vibration absorption system is also offered. The main cabin can be rapidly reconfigured between passenger and cargo-carrying configurations and is accessed via two sliding doors on either side of the cabin, a dedicated baggage compartment is also present beneath the main cabin. PZL- Świdnik stated that multi-role operations had been a high priority during the SW-4's development; and that the rotorcraft is well-suited to passenger transport, primary and advanced training, patrol and surveillance missions.

Various optional equipment can be installed, such as removable co-pilot flight controls, wire-string protection, a forward looking infrared (FLIR) sensor system, instrument flight rules (IFR) training fittings, radio altimeter, emergency medical system, moving map, external loudspeakers and/or search light, flotation gear, and an external cargo sling. Much of the external equipment is designed to be held on external extension arms; overall, the SW-4 can mount/carry a useful payload of up to nearly 600 kilograms. Both basic and advanced trainer variants of the SW-4 have been developed to conform with NATO standards and military pilot training regulations, it is promoted as possessing a high level of inherent flight stability and safety; the advanced model is compatible with night vision goggles (NVG) and is equipped with an emergency simulation unit.