Autobiographical memory (AM) is a socially-relevant cognitive skill. Little is known regarding AM during early childhood in ASD. Parent–child reminiscing conversations predict AM in non-ASD populations but have rarely been examined in autism. To address this gap, 17 preschool-aged children (ages 4–6 years) with ASD and 21 children without ASD matched on age, sex, and expressive language completed assessments of AM, executive functioning, self-related variables, and a parent–child reminiscing task. Children with ASD had less specific AM, which related to theory of mind, self-concept, and working memory. AM specificity also related to child observed autism traits. Mothers of children with ASD made more closed-ended and off-topic utterances during reminiscing, although only maternal open-ended elaborations predicted better AM in ASD.