This case study chapter reviews the evidence related to TransMilenio (TM) and its ability to promote walking among Bogotá’s citizens. A historical perspective of the Bus Rapid Transit system in Latin America and Bogotáis provided as well as some of the social, environmental and cultural implications. Through a literature review, studies that specifically assessed the role of TM in the promotion of walking and active transportation were identified. In addition, experts in the field were contacted to receive additional papers or reports from the grey literature that could have been missed through the peer-reviewed literature search. In December 2000, Bogotáimplemented TM. The system has been successful in reducing traffic congestion, environmental pollution and travel times, as well as improving mobility in the city. Although not initially a goal of TM, some evidence suggests that the system has also served to promote walkability in the city. TM users are more likely to meet recommendations for daily moderate-to-vigorous physical activity and for walking for transportation, reaching an average of 22 minutes per day. Despite its many benefits, TM has some shortcomings that need to be recognised and addressed. In 2014, the daily number of TM users (2.2 million) surpassed the number of users of the traditional public transportation system, but there has still been a migration of users to private means of transportation such as motorcycles and automobiles.