The intensive developments of the 1920s were crowned by the huge General National Exhibition () of 1929 that was visited by 4,5 mln people. This was the year that the Great Depression began. Despite the difficult economic situation, the PIF survived and at the end of the interbellum it was one of largest companies of its kind in Europe. During World War II, the company ceased to exist, its infrastructure was confiscated, and turned into a factory of Focke-Wulf, which made the PIF a military target for the Allied air forces. This led to great destruction of its infrastructure in 1945. During the war 85% of the PIF was destroyed, but despite this damage, the first postwar exhibition took place in 1946 and one year later, in 1947, the PIF had already regained its international character. In 1990 the Poznań International Fair transformed into a limited liability company with the State Treasure as one of its shareholders Since then the PIF is continuing to expand and enlarge its exhibition space.