Here we examine imaginative drawing abilities in children with Autism Spectrum Disorder (ASD) and learning disabilities (LD) under several conditions: spontaneous production, with use of a template, and combining two real entities to form an ‘unreal’ entity. Sixteen children in each group, matched on mental and chronological age, were asked to draw a number of ‘impossible’ pictures of humans and dogs. Children with ASD were impaired in spontaneous drawings and included fewer impossible features than children with LD, but there was no difference when a template was provided. An autism-specific deficit was revealed in the task involving combining entities. Results suggest that children with ASD do not have a general imaginative deficit; impairment is instead related to planning demands.