The purpose of this study was to investigate symptoms of comorbid disorders in infants and toddlers with autism spectrum disorders (ASDs). Research is scant on symptoms of co-occurring mental health conditions in this very young population. Method: Three hundred and twenty four participants were included in this study. Participants were classified into one of three groups: Autistic Disorder, Pervasive Developmental Disorder-Not Otherwise Specified, and control. A Multivariate Analysis of Variance (MANOVA) was utilized to assess group differences on the six subscales of the "Baby and Infant Screen for Children with aUtIsm Traits-Part 2" (BISCUIT-Part 2). Results: The MANOVA revealed a significant main effect for group. Follow-up analyses showed that all subscales contributed to the significant main effect of the MANOVA. Discussion: The results of the analyses in this study are consistent with the current literature on older children and adults with ASDs. Implications of early identification of comorbid disorders are discussed. Further research on the mental health of infants and toddler with autism spectrum disorders (ASDs) is warranted. (Contains 1 table.)