In this work, a monitoring experience of student workload and attendance is presented. During four academic years, from 2015 until 2019, first-year students of an Engineering degree have been asked, three times a week, to estimate their autonomous workload devoted to the Statistics subject. The monitoring strategy has been anonymous, open and voluntary and has shown a high ratio of participation: 407 students out of 433. To generate the final dataset this information has been combined with attending records to classroom-based lectures and final grades achieved. Results indicate that declared student’s workload hardly reaches the 90 hours of autonomous work established in the ECTS ratio of our university. Nonparametric comparisons show strong statistical evidences of the relationship between final grades in the subject and declared workload and attendance. We find that attendance is crucial in order to achieve a homogeneous workload along the semester and a success in the subject’s grading.