The Czech Army was disbanded following the dissolution of Czechoslovakia in 1939; Two Czech Brigades formed, one in Britain, one in the Soviet Union, that fought against the Germans during the war. Czech military equipment, esp. soft-skinned vehicles, tanks and artillery were utilized in large numbers by the Wehrmacht during the war.

Hungary contributed a mechanized force to Operation Barbarossa, and later deployed it's Second Army on the Eastern Front. It was essentially destroyed in the fighting around Voronezh, during Operation Little Saturn. Hungarian troops continued to serve in rear area capacities, before serving again in a frontline capacity when the fighting entered Hungarian borders. The First Army attempted to defect when Hungary tried to switch asides, but both failed. The Hungarian Army continued to fight alongside the Germans until the end of the war, and was involved in the defence of Budapest.

Romania's Third and Fourth Armies accompanied the German Eleventh Army during Operation Barbarossa, but suffered terrible losses in the Siege of Odessa. The Romanian Mountain Corps fought in the Siege of Sevastopol, and the Third and Fourth armies formed the flanks of German Sixth Army and Fourth Panzer Army during the Battle of Stalingrad, collapsing and allowing Operation Uranus to encircle the German positions. Romanian troops again fought through the Ukraine, and in the Crimean peninsula, and fighting reached the Romanian border. In the Summer of 1944, Romania defected to the Allies, though it's armies fought hard against Red Army attacks, before standing down. German Sixth Army was encircled (again), and the Romanian army fought alongside the Red Army until the end of the war.