Darkness is a barrier to cycling because the risk of an accident is higher and the feeling of social safety is lower. Factors influencing the choice to cycle (e.g., socio-demographic factors) have already been studied extensively, but rarely in relation to darkness. To implement strategies for increasing bicycle use (also when it is dark), we need to know what decision factors play a role for people to cycle or not when it is dark. A mixed method approach is adopted; applying a logistic regression using data of 842 surveyed cyclists in the province of East Flanders (Belgium), supplemented a qualitative analysis using 26 in-depth semi-structured interviews. Results show that knowing and using a route frequently has a positive effect on the likelihood of cycling in the dark. Elderly (and retirees) are less likely to cycle in the dark compared to youth and young adults. The latter group (ranging between 11 and 17 years old) often cycle to school while it is still dark (either or not accompanied by a parent). Whether or not one cycles alone or in group has a lower or higher propensity to cycle during the dark. People with a racing bike often cycle in groups and are less likely to cycle in the dark. Recreative and sportive cycle tours are mostly done during the day. Cyclists with an e-bike and speed pedelec have a higher likelihood to cycle in the dark compared to those who cycle on a regular bike. Women have 84% lower odds to cycle in the dark compared to men because they perceive darkness as less socially safe. Lastly, living in a rural environment has a positive impact on the odds to cycle in the dark compared to more urban environments. Establishing a cycling culture with inclusive infrastructure is essential for addressing the diverse needs of vulnerable groups and ensuring the provision of safe routes. A holistic approach is critical to effectively integrate these elements into urban planning and transport policies.