Previous cohort studies have reported relationships of active commuting, walking, and cycling with mortality. No studies have separately examined commuter and recreational cycling and how changes in cycling are related to mortality. Prospective cohort study among individuals who were between 50 and 65years and living in Denmark at the baseline examination between 1993 and 1997. Commuter/recreational cycling and changes in cycling were investigated in analytic samples of 28,204 and 15,272 participants, respectively. Participants were asked to provide information on cycling habits and other risk factors for mortality at baseline and 5years later and were followed for risk of death until July 2013. Data were analyzed in 2018. Cycling between 1 and 60 minutes per week was associated with lower risk of all-cause mortality, with an appertaining multivariable adjusted hazard ratio of 0.76 (95% CI=0.69, 0.83) for recreational cycling and 0.78 (95% CI=0.63, 0.96) for commuter cycling when compared with no cycling. Compared with those who never cycled, the hazard ratio for those who initiated cycling was 0.78 (95% CI=0.67, 0.90) and the hazard ratio for those who consistently cycled was 0.77 (95% CI=0.71, 0.84), whereas the hazard ratio for those who stopped cycling was 0.98 (95% CI=0.87, 1.11). Initiation of, or continued engagement in, cycling late in mid-life is associated with a lower risk of all-cause mortality. It may be suggested that national and local governments prioritize resources to promote cycling.