The scores of TOEFL, TOEIC, and TEPS have been increasingly used for many purposes in Korea. In particular, these test scores are being used as a predictor for determining readiness for and success in college work, or as a measure of the testees' overall English proficiency. Nonetheless, studies have rarely proposed that the validity of the test scores is used for either purpose. As a preliminary step to explore the predictive validity of the test scores, we collected the scores of TOEFL, TOEIC, and TEPS from thirty students of a university as well as their cumulative grade point averages (GPAs). The correlations between the test scores and GPAs show that TOEFL will be most likely to have the highest validity coefficient as a predictor for determining success in college work as well as a measure of overall English proficiency. Although this study has a few limitations such as the small number of participants, their homogeneousness as a group, etc., it provides some insight into the use of the three tests for college admissions and measurement of overall English proficiency and suggests need for conducting further validation studies in these areas.