Background <p>Antibiotic overprescription is a complex global problem that contributes to antibacterial resistance. Enhancing professionals’ communication skills is one of the most promising interventions for optimising antibiotic prescription in respiratory tract infections in children.</p> Methods <p>We developed a communication skills course for primary care paediatricians, paediatric nurses and community pharmacists. We conducted: 1) A scoping review, 2) brainstorming and selection of themes, 3) design of content, 4) user testing, through a survey and semi-structured interviews. A multidisciplinary advisory group gave feedback throughout the design and development process. We conducted a descriptive analysis of the survey results, and we used a predefined analytical framework for qualitative content.</p> Results <p>The course comprised four modules with nineteen themes, which included communication theoretical content, clinical cases, complementary reading, videos, and a glossary. It also included a forum and webinars, after each module. Sixteen users completed several themes and a survey, and eight were interviewed. They rated a mean of 4 or higher (5-point scale), across most of the domains evaluated. The videos received the highest rating (4.81; SD = 0.39). Suggestions for improvement included incorporating a workshop, and featuring more representation of other professionals. The majority of professionals (93%) expressed interest in completing the course.</p> Conclusion <p>We developed a comprehensive, evidence-based online communication skills training course to optimise antibiotic prescribing in paediatric primary care. Integrating key communication strategies and insights from a scoping review, the course equips healthcare professionals with practical tools to enhance shared decision-making and antimicrobial stewardship.</p> Trial registration <p>Not applicable.</p>