Background: Children with mild intellectual disabilities in Malaysia often lack structured, tailored sexuality education. Existing national resources are broad and not diagnosis-specific. This study developed and validated sexuality education guidelines and an activity kit for parents of children aged 4-12 years with mild intellectual disabilities. Method: A four-phase qualitative approach was applied: (i) guideline and kit development through literature review and researcher consensus, (ii) expert review via focus group discussion (n = 6), (iii) content validation index (CVI) assessment and (iv) cognitive interviews with parents (n = 9). Purposive sampling ensured diversity in expertise and parental backgrounds. Results: Experts recommended narrowing the scope, simplifying language, adding culturally sensitive visuals and using interactive tools. CVI scores were 1.00 for all components. Parents confirmed usability, preferred realistic imagery and valued guided dialogue templates. Conclusion: This sexuality education guideline and activity kit is tailored to mild intellectual disabilities, offering a culturally sensitive, interactive and age-appropriate home-based resource.