Factors determining the introduction of cargo bikes in urban commercial transport. One potential approach to the challenges faced by urban commercial transport is the introduction of (electrically assisted) cargo bikes in different transport market segments, which will initially be categorized. Furthermore, this paper deals with the sparsely investigated reasons explaining the gap between cargo bikes’ large potential to substitute car trips and their marginal degree of utilization to date. Inspired by innovation diffusion theories and based on the results of 45 guided interviews with cargo bike users and industry insiders, this article presents three interrelated groups of determinants influencing stakeholders’ decisions to use cargo bikes in a positive or negative way. Firstly, environmentally specific factors consist of regulatory, socio-spatial, and economic framework conditions. Secondly, company-specific factors include the type of fleet decision-making, firms’ strategic orientation, and decision-makers’ individual attitudes. Thirdly, vehicle-specific factors can be grouped in compatibility with transport tasks, relative advantage compared to conventional vehicles, and cargo bike availability.