 To evaluate the possibility of benefit in autistic children, we propose to conduct an open-label trial of the anti-inflammatory antibiotic minocycline, an agent that reduces inflammation by blocking the nuclear translocation of the proinflammatory transcription factor NF-kappa-B. Minocycline is Food and Drug Administration FDA-approved for treatment of a variety of infections and has been widely used for the treatment of adolescent acne. Minocycline is currently in phase III trials for the treatment of Huntingtons disease and amyotrophic lateral sclerosis. 