Our Medical Biochemistry course is a compact, primarily lecture-based course. There are four instructors in the course, each with different teaching styles, emphases and goals. The high density of lectures causes a problem for students who do not adopt strong study habits from the outset of the course since there is no opportunity to catch up. Additionally, the very distinct teaching styles of the participating faculty leave many students frustrated and confused about how and what they should be studying. After trying various strategies with mixed success over the past several years, we have recently implemented a tool that helps to solve both of these problems. The course director worked with the other teaching faculty to write a set of USMLE-format quiz questions that cover key concepts from each lecture. After one or a small set of lectures has been presented, a 5-10 question quiz is released on the course WebCT site. Students have 3 days to complete each open-book quiz. They are encouraged to consult other students and use reference materials. In the spirit of self-assessment, students may re-submit the answers once to improve their score. The WebCT program is set for timed access to the quizzes and manages the grades. The 41 quizzes (317 total questions) count for a total of 10% of the course grade, enough to engage the attention of the students. As the course progresses the quiz questions become progressively more complex, building on previous material. The frequency and progressive nature of the quizzes encourage students to adhere to a more optimal study schedule and to retain previous concepts. These quizzes have increased consistency throughout the course and have helped to focus attention on the key objectives of the more complex lectures. All of the students participated and achieved an average cumulative quiz score of 93%. The vast majority of students reported that the quizzes were very (85%) or moderately (10%) helpful. Importantly, the mean on the comprehensive final exam increased 11% compared to that on a similar exam given the two previous years.