Migration and duration of residence data in the continuous population registers of Copenhagen, Denmark, have been analyzed to ascertain the extent to which repeated migration is a factor in accounting for high mobility rates. The findings, based on the period 1950–1961, support the view suggested by several American studies that stability of residence is characteristic of a large majority of the population. Stability is most typical of the young and the older age groups and least common among those 25–44 years of age, both male and female. But even for the middle age range, at least 70 per cent of the population was stable. The findings also emphasize that the pattern of repeated mobility is most characteristic of a limited segment of the population, a group which shows a particularly strong tendency to move several times over relatively short time spans. This pattern is particularly characteristic of those in the 25–44 year age group. These data emphasize, therefore, that a high degree of residential stability for most of the population is not at all contradictory with high rates of mobility The repeated moves of a small segment of the population inflate the overall mobility rates well beyond what they would be if mobility were based on the number of migrants instead of on the number of moves.