This study investigated the predictive validity of JSCE and Joint SS2 promotion Examination scores on senior secondary school Students’ performance in SSCE in Akure South Local Government Area of Ondo State. This study adopted correlational research and ex-post facto research design. The research work was carried out, using two schools and two hundred and fifty-five (255) students. The scores of students who sat for JSCE 2011, JSS2PE 2013, WAEC 2014 and NECO 2014 were collected through a Proforma and analyzed using regression analysis as well as analysis of variance.
Eight hypotheses were formulated and tested at alpha level of 0.05. The findings from hypotheses indicated that there was a positive but moderately weak correlation between JSCE, JSS2PE and WAEC Mathematics and English. It was also found that there was a positive but moderately weak correlation between JSCE, JSS2PE and NECO Mathematics and English. The researcher also found that JSCE and JSS2PE combined had the ability to predict the performance of students in WAEC Mathematics and English, as well as the combination of both JSCE and JSS2PE on NECO Mathematics and English. It was also revealed that JSS2PE had significant contribution and JSCE had contribution which was not significant in the prediction of WAEC Mathematics and English. The researcher found that JSCE had contribution which was not significant and JSS2PE had significant contribution in prediction of NECO Mathematics and English. These findings also revealed that JSCE had weak predictive strength but JSS2PE serve as better prediction of students’ performance in SSCE.