The aim of this study was to verify the association between internet use and physically active leisure time during four years in older adults included in the “EpiFloripa Idoso” study, a population and longitudinal study with older adults (60+) residents in Florianópolis, Brazil, interviewed in 2009-10 (baseline) and 2013-14 (follow-up). The outcome was self-reported level of leisure physical activity, measured by the long version of the International Physical Activity Questionnaire, classified as remaining inactive; becoming inactive; becoming active; remaining active. Covariates were: gender; age (in years); per capita income in Reais; schooling (years of study); internet use longitudinally measured (remaining not using, stopping using, starting using, remaining using); and cognitive decline at baseline assessed by the Mini Mental State Examination. Relative risk ratio (RRR) adjusted by independent variables were estimated. Participants were 1,705 older adults at baseline and 1,197 at follow-up. The prevalence of remaining physically active during leisure time was 15.8% (95% CI 12.6 to 19.0) and was associated with being male (RRR = 2.14, 95% CI 1.50 to 3.05), less schooling (RRR = 0.99, 95% CI 0.99 to 0.99), starting using (RRR = 4.1, 95% CI 2.06 to 8.55) and remaining using the internet (RRR = 5.52, 95% CI 3.25 to 9.36). This study can contribute to public policies for active and healthy aging through stimulation of internet use, since this technological behavior can help increasing the level of leisure physical activity in this population.