We examined response to oxcarbazepine prescribed for irritability/agitation symptoms in a retrospective case series of 30 patients with Autism Spectrum Disorder (ASD). The average patient was 12.0 years old (range 5-21) and taking two other psychotropic medications (range 0-4). Fourteen patients (47 %) had a clinical global impression of improvement score of "much improved" during treatment. Ten patients (33 %) showed an improvement on their clinical global impression of severity score. Seven patients (23 %) had a clinically significant adverse event or side effect leading to oxcarbazepine discontinuation. Without a placebo group, it is not possible to evaluate whether oxcarbazepine provides benefit for irritability/agitation symptoms in ASD. The high rate of adverse events suggests its use should be accompanied by caution.