This study examines the use of ChatGPT as a design-support tool for developing career promotion content. In the digital transformation of society, areas such as career guidance and promotion are increasingly being reshaped by the speed, scalability, and accessibility of artificial intelligence (AI). Specifically, the study investigates how ChatGPT, a generative AI tool, can function as a design support system in the development of career promotion video content by generating structured interview scripts, profession-specific scenarios, and narrative components. The aim of the study is to identify the strengths and limitations of the ChatGPT-supported content development process, to evaluate the appropriateness of the content according to the feedback from professionals and students, and provide practical implications for educational content development and career guidance. Within the scope of the study, career promotion videos were developed for 38 different professions using three formats: interviews with professionals, a day in the profession scenarios, and critical decision moments. Data collection tools included researcher process notes, expert evaluation forms completed by professionals, and student feedback surveys following video implementation. Descriptive and thematic analyses were used to analyze the data. The findings indicate that ChatGPT-supported content development was perceived to enhance efficiency, scalability, and structured content generation, while human review and expert validation remained essential for ensuring contextual accuracy and professional authenticity. Overall, the findings suggest that conversational generative AI tools such as ChatGPT can serve as valuable design-support systems for educational video content development workflows, particularly in generating structured career narratives and scalable multimedia content. The study provides empirical and design-oriented insights into the integration of generative AI into educational content development and career promotion content development.