He made his theatre début on 1st May 1955, in the role of Władek Sosnowski in the stage drama ,,Miłość ojców” written by Alexander Gorbatov and directed by Stanisław Milski, performed at the Lubuski Theatre in Zielona Góra, where he continued to perform, until 1959. Later on, in the years 1959-1960, he worked at the Adam Mickiewicz Theatre in Częstochowa. In 1960, he moved to Wrocław, where he first worked at Teatr Rozmaitości, in the years 1960-1967 (then renamed to the Contemporary Theatre), and then, in the period from 1967 to 1994, at the Wroclaw Contemporary Theatre.
Medard Plewacki’s professional portfolio also includes film roles. For example, he played in three films directed by Stanisław Lenartowicz, namely ,,Zabijaka” (1967), ,,Martwa fala”/”Calm Flat” (1970), and ,,Opętanie”/”Obsession” (1972). In 2009, he played a Cistercian monk, Father Placid, in ,,Teraz i na zawsze” directed by Artur Pilarczyk, and ,,Jedenaste: nie uciekaj”/”Eleventh: Don’t Escape” directed by Robert Wrzosek.
The actor was also involved in many TV series, such as ,,Na kłopoty… Bednarski” (1986), ,,Złotopolscy” (1998), ,,Życie jak poker” (in the years 1998-1999), or in ,,Fala zbrodni” (2004).
After retiring, Medard Plewacki chose to give lessons in phonetics, for example for clerical students in seminars in the Lower Silesia province, or gives guest appearances in theatres.