The study evaluated the convergent validity of the PEAK-E-PA and two common assessments of language development used in educational and clinical settings: the ABLLS-R and the TOLD-I:4. The PEAK-E-PA provides a measure of a participant's ability to derive arbitrary stimulus relations, and may therefore provide a more complex analysis of language functioning than traditional behavior analytic language assessments. The results of the present study support a strong, significant relationship between the PEAK-E-PA and the ABLLS-R (r = 0.73, p < 0.01), but the obtained coefficient falls within the lower range of prior psychometric evaluations of behavioral language assessments. The results suggest a stronger relationship between the PEAK-E-PA the TOLD-I:4 (r = 0.94, p < 0.01), supporting the use of the PEAK-E-PA with individuals with autism who have progressed beyond the elementary verbal operant skills assessed for in traditional behavioral assessments.