Background: Existing literature failed to explore the parental expectations and experiences from physiotherapy for children with Down syndrome. Hence, we aimed to validate a semi-structured interview guide to explore parental experiences and expectations from physiotherapy for children with Down syndrome. Methods: A 28-item interview guide was reduced to a six-item interview guide and validated through three rounds of Delphi survey in experts with prior experience in children with disabilities. The first and second rounds failed to meet the S-CVI/Ave threshold of 0.90, leading to revisions based on feedback. Results: After suggestions were received from 10 experts with an average of 2 years of experience in dealing with children with Down syndrome, a six-item interview guide was finalised, with I-CVI of 0.78-1 and S-CVI of 0.9. Conclusion: The generated interview guide aimed to explore the experiences and expectations of parents of children with Down syndrome undergoing physiotherapy, found to be valid.