The main aim of the present study was to compare pictures and words with respect to access to semantic systems in autism using a semantic priming paradigm. A word completion task was conducted using both within-modality (word–word, WW) and cross-modality (picture–word, PW) conditions on a group of high-functioning adolescents and adults with autism (N = 20) and a control group (N = 20) matched on chronological age, mental age, Verbal IQ and Performance IQ. Both groups showed semantic priming effects in both modality conditions, generating significantly more responses for related prime-target pairs than for unrelated pairs. Although the control group performed similarly on both priming tasks, the autistic group performed significantly better on a PW task than on a WW task. These findings suggest the possible advantage of pictures over words in access to semantics in autism. The theoretical implications are discussed in terms of functional asymmetry between verbal and pictorial semantic operations that may be specific to autism.