Abstract Background The aim of this paper was to describe the development of an intervention that is developed to improve communication about the heart failure (HF) trajectory and end-of-life care. We also present data that provides a first insight in specific areas of feasibility of the intervention. Methods Co-design was used and patients, family members and health care professionals were constructive participants in the design process of the intervention. Feasibility of the intervention was tested in two areas; acceptability and limited efficacy. Results Two communication tools were designed and evaluated; 1) a Question Prompt List (QPL) for patients and family members and 2) a communication course for professionals which was web -based with one face-to-face training day with simulation. Data on feasibility was collected with questionnaires that were developed for this study, from the 13 participants who completed the course (all nurses). They reported improved knowledge, confidence and skills to discuss the HF trajectory and end-of-life care. The QPL was evaluated to be a useful tool in communication with patients and family members. Conclusions In a co-design process, future users identified the need for a QPL and a communication course. These communication tools can be used as a dual intervention to improve communication about the HF trajectory and end-of-life care. The QPL can help patients and families to ask questions about the HF trajectory and end-of-life care. The communication course can prepare the professionals to be knowledgeable, confident and skilled to discuss the questions in the QPL. Before the tools are ready for implementation in clinical practice, further studies testing the feasibility of the intervention are needed, including also patients and their families.