The ongoing implementation of research-based learning (RBL) within the higher education core curriculum leads to a growing number of students who conduct their own research projects during their course of study. Although previous studies have indicated that research-based learning has positive outcomes for students, their causal link remains unclear given a focus on specific disciplines, and the lack of pre-post designs and control groups. To fill this gap, the aim of our study is to examine how research-based learning, specifically the conduct of the research process by students on their own, affects their self-rated research competences with a longitudinal research design that was conducted in a wide range of disciplines. We used panel data from Germany (N = 520) and applied fixed-effects panel regression models to analyze students within student variance to the treatment effect of research-based learning. Results suggest two main findings. First, engagement in research-based learning significantly increases students' self-rated research competences relating to reviews of the state of research, methodology, reflection on research findings, communication, and content knowledge. Second, the effectiveness of research-based learning differed among students enrolled in bachelor's and master's degree programs.