Firms tap into user knowledge to learn about their users’ needs. While users have been recognised as a valuable source of knowledge for innovation, few studies have investigated how their knowledge is integrated into innovation processes in the context of complex products and systems (CoPS). The purpose of this study is to reveal how manufacturers of CoPS utilise user knowledge for innovation. We investigate two case companies, a medical device manufacturer and an aircraft manufacturer, and report on seven managerial practices for utilising user knowledge. We adopt the absorptive capacity model in structuring our findings and elaborate three of the model’s sub-capabilities (recognition of the value of user knowledge, acquisition of user knowledge, and assimilation/transformation of user knowledge) by proposing that each is associated with a distinct managerial goal and related practices: 1) Sensitising the organisation to the innovation potential of user knowledge, 2) identifying and gaining access to suitable user knowledge, and 3) analysing and interpreting user knowledge and integrating it into product development. Our study contributes to the innovation management literature by analysing the capabilities required to utilise user knowledge throughout the CoPS innovation process.