Since Benno Geyer fails to pass his Abitur due to his panicky exam anxiety, Dr. Fritz Geyer enrolls in high school under his brother's name. As a model student, he has no trouble getting good grades, but he quickly becomes unpopular among the students. From then on, he tries to impress with the craziest pranks.
| Actor | Role |
|---|---|
 Peter AlexanderDr. Fritz Geyer | Dr. Fritz Geyer |
 Cornelia FroboessReny Pacher | Reny Pacher |
 Gunther PhilippDr. Erwin Berthold | Dr. Erwin Berthold |
 Gusti WolfFrl. Puppernick, Sekretärin | Frl. Puppernick, Sekretärin |
 Wolfgang JansenBenno Geyer | Benno Geyer |
 Rudolf CarlErich Pacher | Erich Pacher |
| EElisabeth EppMathilde Pacher | Mathilde Pacher |
 Joseph EggerDienstmann | Dienstmann |
 Adrienne GessnerElisabeth Geyer | Elisabeth Geyer |
| FFranz StoßProf. Kramm | Prof. Kramm |
| OOtto LoeweDr. Oberwasser | Dr. Oberwasser |
| EEdith SteinacherUschi, Bennos Freundin | Uschi, Bennos Freundin |
| FFranz ElkinsPepi, ein Lausbub | Pepi, ein Lausbub |
 Theo LingenProf. Dr. Liebreich | Prof. Dr. Liebreich |
| RRosl DorenaAnna, Haushälterin | Anna, Haushälterin |
| PPeter FrickEwald Adler | Ewald Adler |
| HHeidi GrüblGussy | Gussy |
| WWalter LehrSchutzmann | Schutzmann |
| PPeter MachacSterzenbach | Sterzenbach |
 Raoul RetzerWerkmeister Anton | Werkmeister Anton |
| AAnni SchönhuberAufräumefreu | Aufräumefreu |