Serving in the bomber, reconnaissance and ground-attack roles, it also assisted in the development of ejection seats and air-to-surface guided missiles until its replacement by the Saab Lansen in the late 1950s.

Intended as a replacement for the Junkers Ju 86 in service with the Swedish Air Force,[1] the requirement that led to the Saab 18 called for a three-seat fast reconnaissance aircraft.

[2] Armament consisted of three 13.2-millimetre (0.52 in) machine guns, one fixed firing forwards and controlled by the pilot, the others being in flexible defensive mounts for use by the navigator and bombardier.

[2] By the late 1940s, the third crewmember's position had been eliminated, reducing the crew of the aircraft to two; the provision of air-to-ground rockets and improved bombsights had removed the requirement for a bombardier.

By this time the Saab 18 had established a reputation for suffering a serious rate of attrition, and this led to the decision to outfit all of the surviving aircraft with ejection seats for the pilot and navigator/gunner.

The Swedish Air Force has shown interest in the matter due to the plane's three crew members never being found nor buried.