The electricity sector is in the midst of a structural change driven by new technologies. In Brazil, the electricity sector regulation has mechanisms to foster innovation, including investments in R&D. Recently, the regulatory agency and the industry have been calling for approaches to increase the rate at which R&D departments generate solutions that end up being adopted. As a result, novel approaches to R&D project management have entered the agenda. In this context, the objective of this paper is to characterise Agile Product Development and its application in a highly regulated sector. The paper presents a systematic literature review with the debates about Agile and new product development. Then, a case study exploring an early adoption of the Agile approach in R&D project management in the Brazilian electricity sector is presented. Results include the identification of the Agile features most frequently mentioned in the literature. Moreover, the case study explores the Agile features that were more easily absorbed in early adoption, such as iterative patterns, and discusses implementation challenges in team structure, feedback loops, and communication.