Crafting and stimulating service innovation is considered a main research priority and remains a challenge for service providers. One suggested component of stimulating service innovation is customer creativity. Customers who adapt, modify and transform services or products to better suit themselves are increasingly being recognized as a source of competitive value and innovation. It has been proposed that understanding and supporting the customer’s value creating practices is the key to creating and sustaining value over time in health care. Health services directly address a customer’s well-being and have a significant impact on his or her quality of life. In these types of services, the service outcome is highly dependent on the activities of the individual customer. Health care services often require customers to participate extensively, over long periods of time, with limited support and control. Health services also stretch far beyond the particular service setting into the customer’s daily life. While research, policy, and legislation have all emphasized the active role of health care customers, such customers have traditionally had few opportunities to design their health care services. Nevertheless, health care customers solve health-related problems and engage in self-care and medical decision-making on a day-to-day basis, although this creativity is often unknown to the service provider. To understand how health care customers can enable service innovation, this thesis seeks to conceptualize and investigate the concept of customer creativity in health care. The thesis focuses on customer creativity, not only as an outcome, but also as a dynamic and contextualized process that can be enhanced. The thesis combines insights from health care research with service and innovation research to provide build a framework for health care customer creativity. Building on five papers, the research develops an understanding for health care customer creativity. The individual papers are based on systematic literature reviews as well as empirical data in the form of customers’ ideas for service innovation collected through diaries. The results of the thesis suggest that despite the negative nature of the service, health care customers are creative. Given the opportunity, health care customers can provide creative ideas and solutions on a multitude of aspects, both within and outside the health care setting. This provides the potential to view the health care experience through the customers’ eyes and take part in their creativity in spheres where the service providers have not traditionally had any access. This thesis contributes to the literature by providing a framework for health care customer creativity that recognizes the concept as a complex interplay of factors operating at the individual, contextual, and situational levels. The proposed framework specifies the health care specific factors upon which customer creativity depends, with the intention of positing potential research directions and developing an enriched theory of health care customer creativity.