Rudorffer got his first victory over a Curtiss Hawk 75, on 14 May 1940. He scored eight more times before the capitulation of France. He flew throughout the Battle of Britain, and legend has him being pursued down Croydon High Street below rooftop level by a Hurricane. He achieved his nineteenth victory on 1 May 1941; he was then awarded the Ritterkreuz and appointed Staffelkapitän of 6./JG 2 the following month. By the end of December 1941 he had claimed 40 kills.

In 1942 Rudorffer participated in Operation Cerberus (Channel Dash) and flew over the Allied landings at Dieppe in August 1942. After 45 victories in November 1942 his unit was transferred south to Sicily and later Tunisia. On 9 February 1943 Rudorffer defeated 8 British pilots during a 32-minute aerial battle, and collected his first with multiple victories. Again on 15 February he was victorious over 7 allied aircraft. Among his victories over North Africa are 10 Allied bombers.

In July 1943 Hauptmann Rudorffer was appointed to command II./JG 54 on the Eastern Front. He achieved his first victory here on 7 August. Due to the experience gained by fighting the RAF he achieved incredible success. During his first sortie on 24 August 1943, 5 Soviet aircraft were downed in 4 minutes. On 11 October 1943 Erich Rudorffer wrote history when during 17 minutes he was victorious 13 times.

In the winter of 1944, Major Rudorffer was trained on the Messerschmitt Me 262 Jet fighter. In February 1945 he was recalled to command I./ JG 7. He scored twelve victories with the Me 262, to bring his total to 222.

His tally included 136 on the Eastern Front, 26 in North Africa and 60 on the Western Front including 10 heavy bombers.

Erich Rudorffer started out flying DC-2 and DC-3 in Australia. Later on he worked for PAN AM. In the 1980s he returned to fly for Lufthansa.