It is apparent that engineering is applied science. It can also be argued that knowledge that is not applied is virtually wasted knowledge. The real essence of education is learning to accumulate and apply knowledge for solving life’s problems and so make the world a better place to live. Engineering is one of the formidable fields fulfilling this role. However, admitting students into tertiary institutions without professionally screening them for aptitude in requisite engineering skills is apt to frustrate the achievement of this laudable aspiration. Engineering Aptitude tests are promising assessment tools designed for this purpose. However, psychological tools are of little value, and could even prove fatal, if un-validated. This study, therefore, made an attempt at validating the Pneuma Engineering Aptitude Test [PEAT] for admitting students into tertiary institutions using Federal Polytechnic, Ilaro in Nigeria as case study. For the Ordinary National Diploma [OND] students, PEAT’s predictive power was 51% [R = .507 and r = .507 at p = .001]. For the Higher National Diploma [HND] students, however, PEAT’s predictive power was 18% [R = .181 and r = .181 at p = .271]. This suggests that the predictive validity of PEAT tends to wan with passage of time in tertiary institutions. The implication of this finding was discussed and recommendation for further studies was made in the light of limited data
