Following a pre-war fighter pilot's training, Stefan "Steff" Litjens he was posted to JG 53 in August 1937. At the outbreak of World War II, Uffz. Litjens was serving with 4./JG 53. On 16 October 1939, Litjens was sent to Wiesbaden as a flight instructor to assist with the formation of II./JG 53. He remained at Wiesbaden until 4 November. Litjens then recorded two victories during the French campaign. During the Battle of Britain Litjens recorded another four victories. Over the Eastern front, Litjens was to be particularly successful. He shot down five Russian fighters on 25 August 1941. On 11 September, Litjens shot down two Russian SB-2 twin-engined bombers to record his 22nd and 23rd victories. Later that day, he was engaged in aerial combat with VVS I-16 and MiG-1 fighters while escorting Ju 87 Stukas. During the dogfight, his Bf 109 F-4 was hit and Litjens was forced to baled out of his stricken aircraft, badly wounded he was fortunate to land in friendly territory. He was soon hospitalised but lost the sight from his right eye. When Obfw. "Steff" Litjens returned to active service in October 1942 his unit 4./JG 53 was based in Sicily. Despite his vision impairment. He flew missions over Malta before the unit was transferred to Tunisia. Here he claimed eight Allied aircraft shot down and also flew a number of ground attack missions. This day, on 12 April Litjens followed a Spitfire down to ground level and shot it down 7 km North of Zembra, this was recorded as his 31 abschuss. Two and a half month later, on 21 June Litjens was awarded the Ritterkreuz for 32 victories. Following a lengthy period of leave, Litjens returned to 4./JG 53 on 17 November 1943. The unit was now flying Reichsverteidigung missions. On 22 February 1944, he shot down three USAAF B-17 four-engined bombers. He downed a further two B-17 bombers on 23 March. However, he was again shot down by return fire making an emergency landing. This time he suffered an injury to his left eye which resulted in that his days as a fighter pilot was over. Grounded, he would until the war ended appeal trying to have the decision to refrain him from combat overturned. Oberfeldwebel Stefan "Steff" Litjens is credited with a total of 38 victories in 444 missions. He recorded 17 victories in the East, and of his 21 Western victories, five were 4-engine bombers.