Experiments in the perception and language abilities of autistic children indicate that the children have auditory-visual association problems. These findings, combined with the findings that autistic communication is primarily gestural, led to the teaching of elements of American Sign Language to a 5-year-old nonverbal autistic boy. Results after 20 hours of training indicate that the child did acquire signs, that increasing signing led to increasing vocal speech, and that the child has rudimentary English syntax. The use of Ameslan signs spontaneously generalized to other situations and the training resulted in increased social interaction.