We began open trials of beta-blockers, as adjunctive medication, in eight consecutive autistic adults. The immediate result across all patients was a rapid diminution in aggressivity (Ratey et al., 1987). As time on the drug increased, subtler changes in speech and socialization emerged. While results of open trials must be interpreted with caution, these changes were significant and lasting. We speculate that these effects may be the result of a lessening of the autistic individual's state of hyperarousal. As the individual becomes less anxious, defensive and dearousing behaviors are relinquished and more social and adaptive behaviors appear. There is a concomitant improvement in language, though it is unclear whether lost skills are recouped or new ones developed. Further research is indicated.