Researchers examined the concurrent and predictive validity of a brief (12-item) teacher-rated school readiness screener, the Kindergarten Student Entrance Profile (KSEP), using receiver operating characteristic (ROC) curve analysis to examine associations between (N = 78) children’s social-emotional (SE) and cognitive (COG) readiness with measures of behavioral/emotional risk and early literacy skills throughout kindergarten. Results indicated statistically significant associations between both subscales of the KSEP (SE and COG) with all outcome variables. Findings provide validity evidence in support of the KSEP as an initial gate in the universal screening process to inform educators on the readiness of incoming kindergarteners.