While van Hemessen did create at least two religious paintings, she was mainly a portraitist. Eight small portraits and two religious pictures, with dates between 1548 and 1552, bearing her signature have survived. She portrayed ostensibly wealthy men and women often posed against a dark background. The delicate figures she painted have a graceful charm and are provided with stylish costumes and accessories. Her best-known work is her self-portrait (Kunstmuseum Basel). She inscribed the painting with the year, 1548, and her age, 20 years. Around the same time she also painted a picture of a woman at a spinet, which may have been a portrait of her sister.