Parents and caregivers of 70 children enrolled in a university-based, statewide autism registry (M age = 9.5 years) completed two questionnaires, one generated from criteria outlined in the "Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision" (DSM-IV-TR) and the other the "Social Communication Questionnaire" ("SCQ"), to determine the number of cases likely to have autism. Based on "DSM-IV-TR" questionnaire ("DSM-Q") results, 94.3% met criteria for probable autism. In contrast, 88.6% met criteria for possible autism with the "SCQ." The two instruments agreed on 89% of the cases, and the frequencies of cases meeting criteria on each measure were not statistically different (p greater than 0.05). Results are discussed in terms of their application to the creation of local autism registries. (Contains 3 tables.)