Parents of autistic children face enormous challenges, but very little attention has been paid to their psychological needs. Acceptance and Commitment Therapy (ACT) has previously been tested with parents as part of a comprehensive package, but not yet alone. The present study used a within-subject, repeated measures design to test the effects of a 2-day (14 hour) group ACT workshop on 20 normal parents/guardians of children diagnosed with autism. Parents were assessed three weeks before the workshop, one week before, one week after, and three months after. No significant change occurred while waiting for treatment, but pre to post improvements were found on the Beck Depression Inventory-II (BDI-II), and the Global Severity Index (GSI) of the Brief Symptom Inventory (BSI). Significant pre to follow-up improvements were observed on the BDI-II, BSI, and the General Health Questionnaire-12. Processes measures of experiential avoidance and cognitive fusion also changed and there was some evidence that these changes mediated outcomes seen. Results suggest that ACT may have promise in helping parents better adjust to the difficulties in raising children diagnosed with autism.