Kajsa Ernst worked at Nöjesteatern in Malmo and with the infamous Nils Poppe at the Fredriksdals theatre in Helsingborg (both in Sweden) before she became a regular at Helsingborg City Theatre in the end of the 1980s. She stayed with the Helsingborg City Theatre for ten years and did a number of prominent roles there. Kajsa Ernst now lives in Stockholm and can be seen both at the Stockholm City Theatre in the play "Pepparrotslandet" and as the anxious Pauline in the Guldbagge awarded movie "Tomten är far till alla barnen". In autumn 1999 Kajsa Ernst did a role in the much noted TV-series "One Day At A Time" in an episode about anxiety attacks.