The research field of product-service systems (PSS) has experienced rapid growth since it emerged at the end of the 80s. Consequently, the conceptual structure of the PSS research field has expanded, and this phenomenon has driven novel research topics and future trends. This study analyzes the evolution and conceptual structure of the PSS research field since its emergence. A systematic literature review based on a bibliometric analysis was conducted, followed by a co-keyword analysis and content analysis, aiming to develop a historical overview of the nature of the research. The dataset involved 868 studies published between 1988 and 2022. The results present an analysis of the evolution of the literature in the following periods: (i) from 1988 to 2015, referred to in this study as the ‘past’, and (ii) from 2016 to 2022 (the ‘present’). A comparative analysis of the two periods is carried out, and the main topics and research trends and perspectives for future studies are identified (the ‘future’). Some of the main research topics include digitalization and sustainability, for which discussions on smart PSS, life-cycle management, ecodesign, knowledge management, development of assessment tools, simulation, and modeling technologies, have appeared. Research opportunities for future studies aligned with those topics are also identified, e.g., map key success factors to positive implementation of proposals that reconcile PSS with digitalization.