The purpose of this study is twofold: first, to examine to what extent the time students work on paid jobs is related to study-time (class attendance and time devoted to self-study) and second, to what extent the time students work on paid jobs is related to achievement. A number of 120 students from the problem-based Faculty of Health Sciences in the Netherlands kept a time-diary. Academic achievement was measured by using scores on the block-test. The results showed that working about four to eight hours per week on paid jobs (as opposed to working less than four hours per week or to working intensively, more than 8 hours per week) actually is positively related to study-time. Test-scores are not significantly different among students who are not working on jobs, work some hours, or work a lot.