Responsible Research and Innovation (RRI) is described as a new way of doing science that brings science closer to society. Based on a qualitatively oriented case study, this article supports previous research indicating that researchers face a variety of ethical problems and dilemmas when implementing RRI for the first time. These include difficulties with anticipating and controlling future impacts, an asymmetry of power between project partners and an elusive understanding of the RRI concept. The researchers’ challenges were rooted in conventional (...) research ethics and could be boiled down to one core dilemma: If RRI had been applied from the very beginning of the project period, the chance of realising proof of concept within the scheduled time may decrease. The researchers’ solution to this dilemma was to prioritize proof of concept and postpone RRI activities to later stages of the project. If RRI is expected to live up to its ambition of representing a new way of doing science, more effort is needed at the political level to facilitate change. (shrink)