Children with Autism Spectrum Disorder (ASD) often have impairments in reading comprehension alongside relatively spared word reading; however, studies investigating reading profiles in ASD have been small in scale and few have examined whether word reading skills are underpinned by key foundation skills (e.g., phonological decoding) that need to be in place to support the switch to reading for meaning. This study examined reading (word and text reading accuracy, reading comprehension), phonological decoding (nonword reading) and oral language comprehension (receptive vocabulary) in 49 children and adolescents with ASD and 49 typical peers of the same age. Levels of word and text reading accuracy were within age appropriate levels, but reading comprehension and vocabulary were below average; 31% of the sample showed a significant discrepancy between reading comprehension and word reading accuracy (compared to only 10% of a group of typically developing peers). Even when children with ASD were equated with typical peers on word reading they showed significant nonword decoding difficulties. Variance in phonological decoding was also a significant predictor of reading comprehension for the ASD group (but not for the typical peers).These data suggest that apparent strengths in word reading in ASD may mask basic difficulties with phonological decoding, which, together with weaknesses in oral language comprehension, constrain the development of reading comprehension.