Management of haemophilia involves on-demand or prophylactic intravenous administration of recombinant or plasma-derived replacement clotting factors or bypassing agents. These products are provided as lyophilised powder and diluent, which need to be mixed to produce a solution for infusion. While this process has previously involved multiple time-consuming steps, several reconstitution systems are now available to make mixing easier and more convenient. This study aimed to investigate experience of use and perceptions of the Novo Nordisk MixPro® mixing device among patients and carers using activated recombinant factor VII (rFVIIa) or recombinant factor VIII (rFVIII) with MixPro, and nurse specialists who were either familiar or unfamiliar with MixPro. Nurses were asked to simulate the preparation of an inactive solution using MixPro. Semi-structured interviews were used to gain insight into participants’ opinions of mixing systems in general and their perceptions of MixPro. Likert scales were used to rate the performance of MixPro against predefined characteristics of mixing systems, and the importance of the predefined characteristics to the design of a mixing system. Patients/carers and unfamiliar nurses identified low contamination risk when mixing as the most important characteristic of a mixing system; the most important criterion for familiar nurses was confidence that patients/carers could prepare the system correctly. MixPro was perceived to perform very well overall, particularly in parameters identified as most important. It was described as being user-friendly, simple and quick; its compactness and portability were highlighted as advantages for storage and travel. The main disadvantages reported related to its small components. The majority of nurses said that they were highly likely to recommend MixPro to their patients.