PurposeHow much time students spent on unstructured self-study activities in problem-based learning is not clear. The study addressed this issue by (1) identifying the nature of students’ unstructured learning activities in a problem-based medical curriculum, (2) measuring the unstructured student workload per week and per semester, and (3) assigning European Credit Transfer and Accumulation System units to the medical problem-based modules based on calculating the total student workload. MethodNineteen undergraduate medical students in the pre-clerkship phase were enrolled in the study. Data about the nature of unstructured learning activities and the amount of time spent on them were collected through focus group interviews (n=19); and a log diary method (n=13) describing their unstructured educational activities over one week. A response evaluation model and a thematic description approach were employed for data collection and data analysis respectively. ResultsA broad variations of unstructured learning activities were identified. The unstructured student workload ranged from 33 to 41h/wk., while the total student workload was 63/58h/wk. for years 2 and 3 respectively. The total student workload in a 15-week semester was 945h in year 2 and 870h in year 3, which equates with about 34 and 31 European Credit Transfer and Accumulation System per semester for years 2 and 3, respectively. DiscussionMeasuring student total workload in a problem-based program is important for evading the associated overload, and improving the quality of teaching and learning. Calculating student workload in an integrated problem-based curriculum is a challenge. Total student workload is the foundation for determination of the European Credit Transfer and Accumulation System units. Measuring unstructured student workload (or “out-of-class” learning time) is an important component of total student workload. Assigning the European Credit Transfer and Accumulation System to problem-based programs improves its quality assurance, and has educational, curricular, and organizational impact. Therefore, student workload in such programs should be regularity monitored and evaluated.