Comprehension of biostatistics and principles of research design is important for literature evaluation and evidence-based practice in dentistry as well as for researchers wishing to have their publications accepted by international journals. This Study investigated the contribution of several factors to postgraduate dental student performance in a biostatistics and research design course. All of the subjects in this Study were dental school graduates Currently enrolled in postgraduate programs leading to master's or doctoral degrees. The seven factors selected for study were 1) learning style preferences assessed by the VARK questionnaire, 2) past academic performance at the bachelor's degree level, 3) age, 4) gender, 5) current postgraduate program (master's or Ph.D.), 6) lecture attendance, and 7) performance on a quiz conducted early in the course. Response rate was 64 percent. Using bivariate analysis, a statistically significant relationship was observed between final exam score and the following factors: bachelor's degree grade; having single or multiple learning preferences, having visual, aural, read-write, or kinesthetic learning style preference; percent of lectures attended; and quiz score (P<0.0001, 0.01, 0.02, 0.006, 0.04, 0.03, 0.03, and <0.0001 respectively). In regression analysis, significant predictors of final exam score were bachelor's degree grade, having aural learning preference, and quiz score. The findings suggest that dental educators should direct their attention to students who have difficulties at the beginning of the Course and should match the learning preferences of as many students as possible by presenting information in different ways rather than focusing on a single method of delivering the course.