Kayssler was born in Neurode in the Silesia Province of Prussia (now Nowa Ruda in Lower Silesian Voivodeship, Poland).

At the Deutsches Theater, Kayssler had made friends with director Max Reinhardt, whose Schall und Rauch Kabarett ensemble in Berlin he joined in 1901.

He followed Reinhardt, when he became manager of the Deutsches Theater in 1905, where Kayssler performed in Kleist's The Prince of Homburg, Goethe's Faust and Ibsen's Peer Gynt.

He first appeared as a film actor in the silent movie Welche sterben, wenn sie lieben in 1913 and wrote several poems and dramas.

[4] Ernst Lemmer claimed in his memoirs that after Kayssler was shot, two young women hiding in his home were raped and murdered by the soldiers.