Hand preference was tested in groups of between 40 and 50 autistic children and in sex-, age-, and ability-matched controls. Results were also compared with existing findings on normal children. Small differences occurred between the groups in the directions which would be predicted on the assumption that mental subnormality is associated with delayed development of normal patterns of handedness, and on the hypothesis that autistic children as a group will show a persistent slightly increased tendency to use the left hand. Parents of the autistic group were also assessed for handedness. Contrary to the prediction of slightly increased sinistrality in this group of subjects, some indication of increased dextrality occurred. Results were discussed in relation to possible genetic factors in the etiology of autism.