One promising public health intervention for promoting physical activity is the Ciclovia program. The Ciclovia is a regular multisectorial community-based program in which streets are temporarily closed for motorized transport, allowing exclusive access to individuals for recreational activities and physical activity. The objective of this study was to conduct an analysis of the cost-benefit ratios of physical activity of the Ciclovia programs of Bogota and Medellin in Colombia, Guadalajara in M,xico, and San Francisco in the USA. The data of the four programs were obtained from program directors and local surveys. The annual cost per capita of the programs was: US $6.0 for Bogota, US $23.4 for Medellin, US $6.5 for Guadalajara, and US $70.5 for San Francisco. The cost-benefit ratio for health benefit from physical activity was 3.23-4.26 for Bogota, 1.83 for Medellin, 1.02-1.23 for Guadalajara, and 2.32 for San Francisco. For the program of Bogota, the cost-benefit ratio was more sensitive to the prevalence of physically active bicyclists; for Guadalajara, the cost-benefit ratio was more sensitive to user costs; and for the programs of Medellin and San Francisco, the cost-benefit ratios were more sensitive to operational costs. From a public health perspective for promoting physical activity, these Ciclovia programs are cost beneficial.