Background: Responding to joint attention (RJA) is reduced in young children with ASD despite being vital to the early development of social communication. For this reason, RJA is a frequent target in early intervention programs. Clinical guidelines suggest that exaggerating facial expressions or gestural pointing may improve RJA in children with autism by clarifying the meaning of the gaze or gesture. In the current study, we investigate the effect of intensity of emotional expression on RJA in preschoolers with ASD. Method: Twenty-five preschoolers with ASD and 21 typically developing peers were administered a specifically designed eye-tracking task in which an actor directs attention to a moving object by looking at it with an expression that was either neutral, mildly surprised or intensely surprised. In a supplementary condition, gestural pointing was accompanied by a neutral gaze shift. Results: Commensurate with previous studies, children with ASD oriented less to the face of the actor and were less responsive to RJA when compared to their typically developing peers. However, children with autism differed in their response to RJA according to the different task conditions. They demonstrated more frequent responses to RJA when the actor's facial expression was either intense or supported by gestural pointing. Conclusions: We report initial evidence for the importance of clarifying content cues in order to help preschoolers with autism adhere to receptive joint attention (RJA) opportunities. Our findings inform knowledge about early treatment and attention to emotional expressions in autism and improve our understanding of how early interventions may work to increase RJA in young children with ASD. (C) 2016 Elsevier Ltd. All rights reserved.