In the Turkish community at large, especially among educators, there have almost always been many arguments about the validity of the Turkish University Entrance Test (TUET). The common belief is that the TUET is not a valid measure for academic achievement in undergraduate programs (AAUP). The current empirical research study attempted to investigate whether the TUET is a valid measure for AAUP or not. A Turkish university students sample was selected and the issue was investigated by using two main variables. Namely, the TUET scores and the undergraduate program GPAs. The data were statistically analyzed and interpreted. This research study is important in that it can help provide a solid answer to the ongoing arguments against the TUET and, the most important of all, its findings can be useful for some decision-making processes concerning the construction of the TUET and the student selection and placement for undergraduate programs.