Sternberg, Josef von	...	(Director)
Heinrich Mann, Carl Zuckmayer	...	(Writer)
Emil Jannings	...	Prof. Immanuel Rath
Marlene Dietrich	...	Lola Lola
Kurt Gerron	...	Kiepert - the Magician
Rosa Valetti	...	Guste - the Magician's Wife
Hans Albers	...	Mazeppa - the Strongman
Reinhold Bernt	...	The Clown
Eduard von Winterstein	...	The Director of School
Hans Roth	...	The Caretaker of the Secondary School
Rolf Müller	...	Pupil Angst
Roland Varno	...	Pupil Lohmann
Carl Balhaus	...	Pupil Ertzum
Robert Klein-Lörk	...	Pupil Goldstaub
Charles Puffy	...	Innkeeper
Wilhelm Diegelmann	...	Captain
Gerhard Bienert	...	Policeman

Summary: Immanuel Rath, an old bachelor, is a professor at the town's university. When he discovers that some of his pupils often go into a speakeasy, The Blue Angel, to visit a dancer, Lola Lola, he comes there to confront them. But he is attracted to Lola. The next night he comes again--and does not sleep at home. This causes trouble at work and his life takes a downward spiral.