Abstract Background Interest and effort are key motivational constructs in educational psychology, yet their interplay in learning remains underexplored. Building on Dewey's ( Interest and effort in education , 1913) view that effort complements interest in fostering academic achievement, this research examines their relationship across different learning phases in accordance with a process model developed by Thoman et al. ( The science of interest , 2017). Aims The aim of both studies is to empirically examine the interplay between interest and effort as predictors of learning outcomes. Sample The sample of Study 1 included 152 university students, and the sample of Study 2 included 120 university students. Methods Study 1 comprised two different learning tasks to investigate the relationship between interest and effort. Study 2 made use of a computer‐supported learning environment where additional influences of prior knowledge could be controlled. Interest and effort were assessed before, during, and after the learning tasks. Results The results of both studies indicate that interest and effort serve as positive predictors of learning success and actively complement each other throughout the learning process. Conclusion Findings suggest that although interest stimulates initial engagement, effort is essential for sustained learning, supporting Dewey's view of their interdependence. Educators should foster both interest and effort to enhance learning outcomes.