The topic of acknowledgements has produced abundant research since the 1970s, though, as previous studies point out, the value of acknowledgements has not yet been demonstrated and further research is limited by lack of conceptualization. This study focuses on funding acknowledgements (FAs), considering that funding represents an important input in the scientific process. In this context, 183 scientific publications retrieved from Scopus from the 1970s until June 2020 were analyzed, with the aim of systematizing conceptually this body of research and contributing to a theory of acknowledgements. Results are summarized into the following main themes: the meaning of FAs; data sources for acknowledgements; the process of funding; association of funding with productivity, impact, and collaboration; and other aspects affected by funding. The literature reviewed shows that a theory of acknowledgements based on the reward triangle, as in previous studies, is unable to capture the extreme complexity of the scientific activity affecting and being affected by FAs. Funding bodies appear as clear and influential actors in the scientific communication system, making important decisions on the research that is supported, and influencing the type of knowledge produced. Funding agencies hold a responsibility regarding the data that they may collect on their programs, as well as the normalization policies they need to develop so that funded authors can reference with less ambiguity the financial source of their projects. Finally, the need to assess the impact of research funding beyond the scientific community that is, the societal impact, is also addressed.