INTRODUCTION: This paper aims to present the methods and main results from the Danish occupational mortality studies, and to set the Danish studies into the international context of occupational mortality studies. RESEARCH TOPICS: The first Danish occupational mortality study from 1970-1975 revealed a considerable social class gradient in male mortality where university teachers and farmers had a 40% lower mortality and waiters and seamen had an about 100% higher mortality than the average for economically active men. The social class gradient was less steep for women. A similar pattern was found in 1996- 2005. CONCLUSION: In view of the considerable societal changes which have taken place from the beginning of the 1970s to the turn of the century, surprisingly small changes have taken place in the mortality pattern across social groups.