Enhanced firm-stakeholder interconnectivity has made the environments they operate in more transparent, giving rise to ethical issues that are not always considered. Ethicality should be a concern for firms that recurrently involve external stakeholders in co-creation, due to the mutual dependency these interactions and relationships imply. In the pharmaceutical and medical technology industries, firms have been slower to adopt co-creation, mainly due to legal and compliance regulations. Considering the inherited vulnerability of patients as key stakeholders, these industries are a relevant context in which to study the ethical challenges throughout the co-creation process. Therefore, the aim of the research was to empirically investigate ethical challenges arising throughout the co-creation process and find ways to overcome them. The data were collected via 42 semi-structured interviews with chronic disease patients and managers working within patient co-creation and analysed using NVivo 12 software. Based on the results of the analysis, we developed a framework that identifies and characterises the different ethical challenges throughout the co-creation process. Using Schwarz’s universal moral standards for corporate codes of ethics as a framework, we identified additional moral standards (equality, inclusivity and diversity) that emerged as relevant for the process. Exploring both managerial and patients’ perspectives, we revealed discrepancies in the expectations between managers and patients. Furthermore, we showed that external stakeholders’ expectations are influenced by the stage in which they are involved in the co-creation. The findings are followed by recommendations to overcome such challenges.