Parents of children diagnosed with autism spectrum disorder (ASD) report higher levels of stress than parents of typically developing children. Few studies have examined factors associated with parental stress in early childhood. Even fewer have investigated the simultaneous influence of sociodemographic, clinical, and developmental variables on parental stress. We examined factors associated with stress in parents of young children with ASD. Multiple regression models were used to test for associations between socioeconomic indices, developmental measures, and parental stress. Externalizing behaviors, communication, and socialization skills accounted for variance in parental stress, controlling for ASD diagnosis. Results highlight the importance of interventions aimed at reducing externalizing behaviors in young children as well as addressing stress in caregivers of children with ASD.