After graduating school in 1981, she enrolled at the Free University of Berlin, majoring in German Literature and History. From 1982 to 1986, Martina attended acting classes at the Berlin University of the Arts. During that time, she made her stage debut at the Theater am Turm in Frankfurt. Gedeck performed regularly at the Deutsches Schauspielhaus in Hamburg, and appeared in plays in Basel, Berlin, Frankfurt, and Hamburg.