Purpose: To evaluate the impact of multisensory room (MSR) use on preoperative anxiety and postoperative outcomes in children with autism spectrum disorder (ASD) undergoing dental treatment with general anesthesia. Methods: Forty children, ages six to 17 years, with ASD re- quiring general anesthesia for dental treatment, participated in this study. Participants were randomized to either the control group (standard pre- operative waiting room) or intervention group (MSR) for 20 minutes prior to general anesthesia induction. Pre- and post-intervention preoperative anxiety were measured. Following surgery, postoperative emergence delirium was assessed. Short- and long-term postoperative pain and adverse behavioral effects were evaluated six hours, 24 hours, one week, and one month post-surgery. Data analysis employed repeated measures analysis of variance with two groups and either two or four time periods. Results: The sample was predominantly male (62.5 percent) and identified as either White or Black (53 percent) and non-Hispanic (60 percent). Preoperative behavioral anxiety levels increased post-intervention in the control group (P<0.05) and decreased in the MSR group (P<0.001). Following surgery, pain intensity was greater in the control group compared to the MSR group at six hours (P<0.05) and 24 hours (P<0.01), and similar at one and four weeks. Pre- and post-intervention measures of preoperative heart rate, postoperative emergence delirium, and behavioral effects were similar between groups and over time. Conclusion: These findings suggest a novel, nonpharmacologic technique that can be utilized by various health care specialties to reduce preoperative anxiety and improve post- operative outcomes in children with autism spectrum disorder.