In meiotic cells paired homologues are joined by a set of crossovers known as a double Holliday junction (DHJ). Whether DHJs form during mitotic recombination has been unclear, as mitotic cells possess alternative repair pathways that would not require DHJ formation. Here it is demonstrated that mitotic and meiotic cells form similar DHJs, but that the levels in mitotic cells are approximately 10–fold lower, and show a preference for joints between sister chromatids rather than homologues. Consequently, in mitotic cells non–crossover outcomes are favoured