The first bond formed between a child and his parent, generally his main attachment figure, remains essential for the development of the child’s autonomy. While around 1% of the world’s population is diagnosed with autism spectrum disorder (ASD; Fédération québécoise de l’autisme, 2019), some factors are said to negatively influence the development of the attachment between children with ASD and their parents, explaining why they seem more likely to develop an insecure attachment style (Oppenheim et al., 2012). An explanatory model has been proposed by Lapointe (2017), which suggests that certain factors, such as social communication deficits, associated disorders, and parental stress, could have a moderating effect on the relation between the quality of the attachment and the autistic symptoms. The following article proposes an enhancement of this theoretical model by considering a possible bidirectional link between siblings and parental stress. Keywords: parent-child attachment, insecure attachment style, autism spectrum disorder, parental stress in autism spectrum disorder, siblings of autistic children