The change in subsistence at the Mesolithic/Neolithic transition in Denmark is often characterized as rapid, with a dramatic shift from a marine diet in the Mesolithic to a terrestrial-based diet in the Neolithic. This view has been largely based on the work of Tauber (1981), who observed this dietary shift in stable carbon isotope values for human bone from various coastal sites. Crucial to Tauber's argument are the radiocarbon dates he obtained for each of the isotope samples, for the ages are used to categorize samples as Mesolithic or Neolithic. In this reassessment of his pioneering work, we report on new carbon and nitrogen stable isotope values and radiocarbon dates for Danish Mesolithic and Neolithic humans, including some obtained by remeasuring a number of Tauber's samples. We first briefly describe the Late Mesolithic and Early Neolithic in Denmark and the major characteristics of the transition. We next consider the work by Tauber that has been seminal in studies of the transition. In subsequent sections we present new radiocarbon dates and stable isotope measurements from human skeletal material from the Mesolithic and Neolithic. The concluding discussion summarizes our results and emphasizes the need for more analyses of radio- and stable isotopes from this important transition period.