For a sensitive university admission aptitude screening device like the Nigeria’s Joint Admission and Matriculation Board’s Unified Tertiary Matriculation Examination [JAMB-UTME], it is imperative that the predictive validity be constantly ascertained. The core objective of this study, therefore, was to establish the predictive validity of the JAMB-UTME. The case study and ex-post facto designs were used. The populations of study were the Senior Secondary School Leavers admitted to Nigerian universities via the JAMB-UTME. 8,139 students’ records from a private university in Nigeria constituted the sample. The predictive power of the JAMB-UTME in predicting students’ performance in the university’s semester examinations was tested with regression model. The results suggested that the JAMB-UTME had positive but low indices of predictive validity, which varies across the academic sessions and programmes of study. It was not significant for some programmes. It was recommended that JAMB should embark on a more pragmatic review of the content of the UTME to enhance its predictive validity.