The current field study investigated the weekly use of a reflective electronic (e-)portfolio by 1469 higher education students throughout a term and its effect on exam performance. Students' use of the e-portfolio elements as well as their self-reported use of several learning strategies were documented during a 9-week period. Regression analyses showed that over and above the continuous use and the weekly time spent on the e-portfolio, the reported use of cognitive strategies was a significant predictor for exam grade. Finally, students who used the e-portfolio outperformed their peers without e-portfolio use on the final exam. We discuss results with regard to future implementation and training of the e-portfolio use.