Reading comprehension difficulties have been associated with poor vocabulary knowledge of children with autism spectrum disorder (ASD). Research has shown that Dialogic Reading (DR) interventions may remediate these deficits. The purpose of this study was to compare the effectiveness of two DR intervention protocols on the vocabulary knowledge of four preschoolers with ASD and four age-matched typically developing children. The first was RECALL (Reading to Engage Children with Autism in Language and Learning), which combines DR with evidence-based instructional support to enhance the learning of children with ASD. The second was Adapted Shared Reading (ASR), which consisted of DR question prompts and no additional support. Using a randomised ABAB phase-order within series design, eight participants were exposed to at least four RECALL and four ASR treatment phases. This design allows the comparison of two different conditions (A [ASR] and B [RECALL]). Despite both treatments being successful at teaching vocabulary to the eight participants, greater vocabulary gains were identified in the RECALL condition. Adaptations of shared reading and the use of RECALL in inclusive preschool scenarios are further discussed.