During his long research career, Christensen-Dalsgaard has played a major role in establishing the disciplines of helioseismology and (later) asteroseismology - using the oscillations visible on the surfaces of the Sun and other stars to advance our knowledge of stellar properties, including age, rotation and elemental abundance. Beyond his personal research contributions, he has also done much to set up the necessary infrastructure, both on the ground and in space. In particular, he realised that missions developed to search for extrasolar planets could also provide abundant data for stellar astrophysics.

Christensen-Dalsgaard has received a number of prizes for his work, including the Carlsberg Foundation Research Prize in Natural Sciences and the Rigmor and Carl Holst-Knudsens Science Price from Aarhus University. He is a member of the Royal Danish Academy of Sciences and Letters, an honorary fellow of the Royal Astronomical Society in the U.K. and an international member of the U.S. National Academy of Sciences.