Cycling is gaining increasing attention as a convenient, environmentally friendly, and fitness-improving mode of transport. While many policy interventions have been made to promote cycling, not enough research has focused on the barriers to implementing pro-cycling policies. For effective policy implementation, identifying major barriers and removing them is critical. This study took an in-depth look at Hamburg which started a major cycling promotion in 2008. According to expert interviews and literature surveys, the author found that the major barriers are physical, political and institutional, and social and cultural. Specifically, the city lacks enough physical space, political support, and the evaluation of travel behavior and demand. Also, some private stakeholders are reluctant to give up on-street car parking space for cycling lanes, and the negotiation process is difficult and time-consuming. To overcome these barriers, Hamburg requires cycling-oriented urban design, a strategic and integrated cycling action plan, strong political support, and target group-oriented communication.