Social engagement, pretend play, and concern for another's distress represent fundamental features of typical social-emotional development in the second year. Children with autism spectrum disorder (ASD) display delays and deficits in these areas, and research on toddlers at heightened risk for ASD (HR; younger siblings of children with ASD) indicates these deficits may be apparent in toddlerhood. Prior research has examined these aspects of social-emotional development individually in HR toddlers. The present paper examines them jointly as predictors of ASD. We show that social engagement, pretend play, and empathic concern at 22-months each contribute uniquely to predicting later ASD diagnosis with high specificity and moderate sensitivity. Results have important implications for early diagnosis and intervention in young children with ASD.