This study was conducted to determine the preferences of medical and health science students about various study habits and to evaluate the effect of study habits on academic performance. This cross-sectional survey conducted in the college of medicine and the college of health science of King Saud bin Abdulaziz University of Health Sciences (KSAU-HS) from academic year 2014-2015. A total of 150 undergraduate, medical and health science, male students were selected randomly. Data collected through the validated questionnaire consisted of two parts including demographic questions and 67 items specific to study habits. The total completed questionnaires were 121 (response 80%). Their age ranged from 18 to 23 years with a mean age of 20.2 ± 1.73. Cronbach's a reliability test of the questionnaire was .90. The average grade point average (GPA) of students was 4.62 ± 0.39. The higher mean scores of students for different components of study habits were metacognition out of five 4 ± 0.7 (median = 3.9) and concentration 4 ± 0.6 (median = 3.75). The least mean scores of students for different components of study habits were information discrimination 3 ± 0.6 (median = 3.0) and time management 3 ± 0.6 (median = 3.2). Only "information discrimination" (p = < 0.01, r = 0.311) and "motivation" (p = < 0.05, r = 0.201) and to lesser extent "metacognition" were associated significantly with GPA. A significant correlation between time management and age was found (p < 0.04). Positive study habits have an impact on the academic achievement of medical students. Information discrimination, motivation and metacognition were associated significantly with GPA, while a significant correlation was also found between time management and age.