The present study attempted to investigate an application of the theory of Successful Intelligence (Sternberg, 1997) in lower Greek secondary schools, through a school tests believing that school assessments should be based on solid, empirically investigated theoretical foundations. The test was administered to 2663 students with a mean age of 13.39 years, all studying at the 2nd year of the lower secondary school in 49 schools from different geographical areas in Greece. A confirmatory factor analysis demonstrated the validity of the theory. The findings suggested that Greek pupils have a relatively developed analytical ability; however, the cultivation of their creative and practical skills should be at the focus of Greek schooling.