In Mannheim Ochsenheimer wrote his first stage comedies ("Er soll sich schlagen", "Der Brautschatz"). At the age of 27 he decided to follow a career as an actor and entered into Quandt's troupe of actors in Bayreuth. His first appearance was on 12 November 1794 as Flickwort in Gotter's "Schwarzer Mann". After trying his hand in several fields – he was engaged as an opera tenor for a while – he finally committed himself to acting after successes as Gebhard in "Portrait der Mutter" and as Fallbring in "Dienstpflicht". In 1796 he responded to a call from the Döbbelinsche Bühne (Döbbelin stage) in Stargard. On his way he stayed in Leipzig where he performed at the kürfürstliches Hoftheater (prince-elector's court theatre) as Fallbring and as Stepanoff with the result that he was immediately engaged. So after fulfilling his obligations in Stargard and in Frankfurt/Oder he came to Dresden in early 1797 and became one of the most popular members of an actor company that played alternately in Leipzig and in Dresden. In 1798 symptoms of stress and overstrain began to manifest themselves and his doctor recommended more exercise. Taking long walks in the country Ochsenheimer's interest in lepidopterology was rekindled ""and without noticing it he had, in seeking recovery from one task, taken over another, not less laborious one."" Around this time he made the acquaintance of playwright Friedrich Treitschke who was returning from Switzerland to Leipzig and who shared both his interest in acting and in lepidopterology. In 1801 Ochsenheimer played Talbot in Schiller's "Die Jungfrau von Orleans" (The Maid of Orleans) with Schiller attending the performance of 17 September and praising Ochsenheimer's accomplishment. He was now offered guest parts at most major theatres in the German-speaking countries.