Physical activity is one of the most important health behaviours associated with the prevention and management of chronic diseases in older adults, but this potential is often insufficiently used. The present study examined for the first time whether a positive view on ageing (PVA) may contribute to a higher level of physical activity. Analyses were based on the German Ageing Survey, a longitudinal population-based survey (N = 4034) on middle-aged and older adults (40-85 years) conducted in the years 1996 and 2002. As hypothesised, middle-aged adults with a PVA not only engaged in physical activity in the form of sports more frequently; they even increased this activity provided that they were healthy enough to do so. For older adults, PVA was particularly associated with more regular walking and increases of walking over time. Because walking is often still recommended in spite of health problems, it was remarkable that even older people with worse health walked just as regularly as those with good health, provided that they had a positive view on ageing. The results shed some light on recent findings about the importance of PVA for health and longevity and point to a partial mediation between PVA and health by physical exercise.