Early identification of toddlers and preschool-aged children with autism spectrum disorder (ASD) is important for ensuring that these youth receive targeted early intervention services. Identifying young children with ASD is complicated by overlap among symptoms of ASD and other developmental delays. Additionally, youth with ASD have a higher risk of experiencing co-occurring challenging behaviors that are beyond the diagnostic criteria for ASD (e.g., attention difficulties, anxiety). Given this, broadband behavioral assessments that measure symptoms of ASD as well as other behavioral and emotional challenges offer a cost-effective method for screening young children. The present study evaluated the utility of one such assessment, the Behavior Assessment System for Children, Second Edition, Parent Rating Scale-Preschool (BASC-2 PRS-P), for identifying young children with ASD from those with other diagnoses (including other developmental delays) and those without diagnoses. The sample included 224 toddlers and preschoolers (age range: 24–63 months, males n = 153 [68 % total sample]) who screened positive on an ASD-specific screening tool. Results demonstrated that the Developmental Social Disorders (DSD) scale on the BASC-2 PRS-P had adequate sensitivity and specificity values when distinguishing youth with ASD from those without any diagnoses, but not when differentiating between youth with ASD and those with other diagnoses. Similar to other multidimensional behavior rating scales, the BASC-2 PRS-P may be most useful for identifying young children who require comprehensive diagnostic evaluations.