Background: Anxiety related to uncertainty is common in autism. Coping with Uncertainty in Everyday Situations (CUES©) is a parent-mediated group intervention aiming to increase autistic children's tolerance to uncertain situations. A pilot study was conducted to test its feasibility and acceptability. Methods: Parents of 50 autistic children were randomised to receive CUES© or enhanced services as usual. Results: All children met the clinical threshold for at least one anxiety disorder. Of the 26 participants randomised to CUES©, 72% attended 4-8 sessions. Parents and therapists reported they found CUES© useful and acceptable. Conclusions: Families were willing to be recruited and randomised, the format/content was feasible to deliver, and the outcome measures were acceptable. CUES© should be evaluated in a clinical and cost effectiveness randomised controlled trial.