Background Little is known about e-cigarette use in French students. Our aims were to estimate the prevalence of e-cigarette experimentation and current e-cigarette use; describe the reasons for using e-cigarettes; explore the vaping experience and identify the profiles of e-cigarette users. Methods We used a sequential, explanatory mixed methods design in a sample of French college students. Quantitative data was collected online for a cross-sectional analysis among 1698 students. Two separate analysis based on the thematic analysis and the Grounded Theory were also performed in 20 semi-structured interviews, focusing former and current smokers also current vapers. Results The prevalence of e-cigarette experimentation was 39.3% (95% CI: 35.2–44.0) and 5.1% (95% CI: 3.2–8.0) of students were current e-cigarette users. Experimentation was opportunistic while current usage was rational, requiring to acquire a personal electronic device, getting used to its technicality, appreciating its availability, discretion, and learning the practice. In this context, three distinct groups of e-cigarette users were identified, based on assumed identity, tobacco and e-cigarette use, the functions assigned to e-cigarettes, and intentions with regards to vaping in the future. Conclusion Despite some limitations mainly related to the participants self-selection, this research showed that while many smokers and former smokers have tried e-cigarettes in this student population, few have continued to use them continuously. Moreover, these current e-cigarette users were a heterogeneous group. Longitudinal studies are needed in young adult smokers for a better understanding of how their tobacco and e-cigarette use affect each other and change over time.