In 1939, Ammann made his first film appearance in the Swiss thriller “Sergeant Studer”, based on the novel by Friedrich Glauser. From the 1950s on he was mainly seen on German television series. In 1961, he starred in the series,” Serie Gestatten, mein Name ist Cox” with Günter Pfitzmann, Ellen Schwiers and Paul Edwin Roth. In 1963, he was one of the jurors in Twelve Angry Men by Reginald Rose. 1966 found Ammann playing in Germany's first color television series “Adrian der Tulpendieb” and additional appearances in series such as “Das Kriminalmuseum”, “Die fünfte Kolonne”, “Der Forellenhof” and “Der Kommissar”. In 1967 he appeared in his only Euro-western “Day of Anger” as Judge Cutchell, starring Lee Van Cleef and Giuliano Gemma. In 1973 he was in the horror film “Hexen – geschändet und zu Tode gequält”.
Ammann found great popularity from 1967 in the title role in the soon to reach cult status, long-lived series “Graf Yoster gibt sich die Ehre” in which he played an aristocratic amateur detective and crime writer. From 1994 to 2000 Ammann was successful in the role of the head of the family in “Die Fallers” a television series. In 1998 he played in Dani Levy’s movie “Meschugge” about alleged Holocaust survivors. In 2005, the then 92-year-old played the title role in Micha Lewinsky's film “Herr Goldstein”, which was honored at the Locarno Film Festival for Best Swiss Short Film.
As a voice actor Lukas lent his voice to such actors as Peter Sellers and Lucky Luke in the film comic book adaptation of 1971.
Today Lukas Ammann lives in retirement in Munich, Germany where he is celebrating his 100th birthday.