In 1946 Kortekaas began his stage career as a clown in the circus Renz . From 1949 to 1956 he was with Ab Smith 's musical-comedy duo The Merry Singers . In 1956, Smith collaborated with Piet Bambergen Kortekaas and continued his career as a circus clown by working with Gerard van Essen to give the famous clownsduo stature Cameos . From the 70s was Kortekaas Van Essen's famous TV duo Peppi and Kokki. Later played Kortekaas include the role of Willie in Tell me Aaa Lowietje and that of the second and third season Baantjer .
- Hoping (1986) and Jelle
- Ciske the Rat (1984) and De Haan
- Too Crazy to Run Los (1981) and Henk
- Peppi and Kokki in the Navy (1976) as Kokki