He commanded SS Panzer Regiment 1 LSSAH during the Ardennes Offensive and is considered to be the primary person responsible for the Malmedy massacre.

From March 1938 he was a platoon commander in the SS standard "Der Führer", with whom he participated in the Polish campaign and won the Iron Cross 1st class.

His evaluation by his superiors however was negative, they considered him to be overreckless and a bad people manager, and Poetschke was transferred to the division Das Reich.

Werner Poetschke then took part in the Balkan campaign and in the battles on the Eastern Front for which he received the German Cross in Gold.

Poetschke was identified by various persons involved and eyewitnesses as the officer directly responsible for giving the order to execute the American prisoners near the Baugnez crossroads, which culminated in the Malmedy massacre.