We evaluated the cost effectiveness of preventive home visits to elderly persons in Denmark alongside a 3-year randomized controlled study. The main outcome measure was incremental costs per active life-year gained. The number of active life-years was defined as those during which the person is able independently to transfer, walk indoors, go outdoors, walk outdoors in both pleasant and poor weather, and climb stairs. In 17 of 34 municipalities health visitors and general practitioners were offered geriatric training, which focused on early signs of disability, physical activity, and interdisciplinary follow-up. The remaining 17 municipalities offered preventive home visits as usual. Outcomes were measured in 4,034 persons aged 75 or 80 years old and dwelling at home. The difference in mean total costs between the intervention and the control group discounted at 3% was -856 euro (95% CI -2,455 to 744) in 75-year-olds and 694 euro (-2,684 to 4,071) in 80-year-olds. The discounted difference in mean active life-years was 0.034 (-0.058 to 0.125) and 0.197 (0.013 to 0.380), respectively. The study did not provide conclusive evidence on the cost effectiveness of the programs under consideration.