Knowledge and its propagation are unquestionably at the center of most, if not all, discussions on innovation, performance, as well as other elements related to firm success. Although the literature has proposed several key success factors for knowledge sharing within a firm, it has yet to explore how these factors rank in terms of importance from a firm nationality perspective. Through a Delphi method approach, upstream professionals from four major multinational Oil and Gas firms (Brazilian, North American, Norwegian, and French) ranked specific literature‐based proposed factors for successful intrafirm knowledge sharing. There were a total of three rounds, where the first round had 41 participants, and the remaining two rounds had 39 participants. On average, open door policy and organizational culture were the most relevant factors that lead to knowledge sharing within the four firms. In terms of the least relevant ones, acknowledgement and status were seen, on average, as factors less likely to lead to intrafirm knowledge sharing. Lastly, it can be concluded that the Oil and Gas industry is very homogeneous regarding intrafirm knowledge sharing as the outcomes accrued from this work are very similar regardless the nationality of the Oil and Gas firm.