The distribution of dental caries was determined in complete and partial human dentitions from a 17th century (1621–1640) city graveyard excavated in Gothenburg, Sweden. Sixty-three adults and two children, divided into five different age groups, were studied. Altogether 949 teeth (943 permanent and six deciduous) were examined macroscopically using a dental probe and X-rays. A high number of teeth had been lost post-mortem. An increase in ante-mortem tooth loss was found with increasing age. Sixty per cent of all individuals and 12% of all teeth showed signs of caries. The number of carious teeth per subject increased with increasing age. The highest prevalence of individuals with caries was found for the age group 26–35 (69%). Caries were most prevalent in the first, second and third lower molars (60%), while the incisors and canines in the upper and lower jaws were the least affected teeth (1%). The occlusal surface was the area most susceptible to caries (45%), followed by the buccal cemento–enamel junction (16%) and the approximal contact point (11%). This study shows that, although consuming a diet believed to have been lower in sugar content compared to modern populations, caries did affect a rather high number of individuals living in Sweden during the early 17th century. Copyright © 1999 John Wiley & Sons, Ltd.