ObjectiveThe main objective of this study was to compare the predictive value of admission criteria for students’ grade point averages (GPAs) over a 3-year period for a cohort of students enrolled in health and non-health science professions during the 2012–2013 academic year at Imam Abdulrahman Bin Faisal University (IAU).Materials and methodsThis longitudinal, retrospective cohort study was conducted at eight colleges (four health and four non-health colleges) in IAU between December 2017 and February 2018. The high school grades, aptitude test scores, achievement test scores, and GPA scores over a 3-year period for students admitted during the 2012–2013 academic year at health and non-health colleges at IAU were used. The data were analyzed using descriptive and inferential statistics.ResultsPositive, significant correlations (P<0.01) were found between the three admission criteria and the annual GPA scores (r ranged from 0.192 to 0.499 and from 0.359 to 0.588) for both the health and non-health colleges. High school grades were the most significant predictor of annual GPAs (β=0.340, P<0.01 and β=0.374, P<0.01), followed by achievement test scores in both health and non-health fields of study, respectively. Aptitude test scores were not good predictors of GPAs for the health and non-health colleges.ConclusionHigh school grades are the most important predictor of student GPAs at health and non-health colleges. Changing the weighting criteria in our institution to place more emphasis on high school grades, as our findings indicate, should be considered during the admission process.