The purpose of the current study was to determine the relationship between the PEAK Relational Training System Assessments and the Kaufman Test of Educational Achievement, Third Edition long form in children with autism and other cognitive or language delays. 29 participants were administered the PEAK Relational Training System Battery of Assessments and the Kaufman Test of Educational Achievement. This study sought to extend previous literature examining the validity of PEAK Assessments as compared to previously validated assessments as well as add to the body of literature examining the relationship between academic achievement and language and cognition development. Understanding the interaction between verbal behavior skills, derived relational responding, and academic skills may enable clinicians and educators to serve their learners in a more effective, comprehensive way. The results of this study suggest there is a moderately strong, statistically significant relationship between the PEAK assessments and the Kaufman Test of Educational Achievement Academic Skills Battery Composite (r=0.6675, p<0.0001, R2=.4455) and a strong, statistically significant relationship with the Kaufman Brief Achievement Composite (r=0.7974, p<0.0001, R2=.5611).