Racial disparities exist in autism diagnosis, and yet, the development of most diagnostic tools has not explicitly examined measurement equity between racial and ethnic groups. We examined the validity of the Toddler Autism Symptom Inventory (TASI), a semi-structured interview developed for diagnosis of toddlers, in non-Hispanic Black/African American and non-Hispanic White children. After controlling for group differences in socio-economic status, no differences in diagnosis, age at diagnosis, mean developmental level, or autism severity were found. TASI ROC curves for both groups, in the overall sample, and in samples stratified by SES, showed high AUC values. Validity of two cutoff scores was acceptable. Lack of significant differences in TASI score or responses to individual items suggests similar symptomatology. These results provide early support for the use of the TASI in diagnostic evaluations of Black and White children.