In 1963, a random sample study was performed in Turku, including 405 subjects over 65 years of age. In this study, urinary tract infection was detected in 11 % of the men and in 33 % of the women. Re-examination of the subjects was performed in 1968, 5 years later. During the follow-up period, half of the subjects had died. The mortality was greater among those female subjects in whom an infection was detected in the initial examination than among those with no infection. Among the initially non-infected subjects, a significant bacteriuria was detected, after 5 years, in 7 % of the men, and in 13% of the women. Among the initially infected subjects, bacteriuria was present after 5 years in 14% of the men and in 41 % of the women.