We report on a case of a 6-year-old female with partial trisomy 8p(21-23) associated with autism, mild dysmorphic features, and moderate learning disability. Although mental retardation is a common finding in patients with mosaic trisomy 8 or partial trisomy of various regions of chromosome 8, only two cases associated with autism have been reported so far. Also, in our case clinical manifestations were mild compared to other patients with duplication of the same region of chromosome 8. Although there has been no strong evidence for linkage on chromosome 8 in any of the genome-wide linkage studies so far, the possibility that this segment includes genes involved in the etiology of autism should be further explored.