Against the backdrop of the global challenge of climate change, the concept of sustainable mobility has gained significant attention. Governments, organizations and individuals are increasingly adopting green transportation practices to reduce carbon emissions and create greener and smarter cities. Despite the growing awareness and intention to sustainable mobility, a significant gap remains between individuals’ intentions and their actual behavior; this phenomenon is well known as the intention-behavior or green gap. However, an up to date analysis that evaluates existing evidence to develop overarching approaches for further research is still lacking. Against this background we conduct a systematic literature review to explore the reasons for the green gap in the (urban) mobility context. Therefore, we have included research from different disciplines in our analysis. Based on our analysis, we propose measures to reduce the gap and develop a research agenda to stimulate future research in this area.