The second French Community Innovation Survey (CIS) indicates that 14% of R&D collaborating firms had to abandon or delay their innovation projects due to difficulties in their partnerships, an outcome which we term “cooperation failures”. Controlling for sample selection on the cooperation decision, our estimates show that firms collaborating with competitors and public research organizations (PROs), especially when they are foreign, are more likely to delay or stop an innovation project because of difficulties encountered in their R&D partnerships. More surprisingly, firms collaborating with their suppliers also face a higher risk of “cooperation failures”. At least for PROs, firms can reduce the risk of “cooperation failures” through previous experiences in partnerships. Larger firms and group subsidiaries are less likely to face “cooperation failures”, and so do firms in industries with a strong appropriability regime.