This essay deals with the diseases osteoporosis and osteoarthritis in a medieval population from Visby in Sweden. The aim has been to evaluate to what extent and in what way these diseases have influenced the people of a relatively large harbour town during the Middle Ages. 24 individuals were analysed osteologicaly and 19 of them became subject for measurements of bone density through DEXA readings. Furthermore four individuals were x-rayed based on external differences due to osteoarthritis and a change in the depression at the base of the medial surface of the greater trochanter. Similar studies have been made in Trondheim, Norway and Wharram Percy, Great Britain.