I experimentally examine whether disclosure of corporate social responsibility (CSR) investment facilitates cooperation in business collaborations. Business collaborations are essential for firms to maintain their competitive advantage. However, half of all ventures fail. A major reason for this high failure rate is a lack of cooperation among business collaboration partners, known as relational risk. Findings suggest that CSR disclosure leads to greater CSR investment, but does not result in an overall higher level of cooperation. However, CSR disclosure moderates the link between CSR investment and cooperation. When CSR investment is disclosed, cooperation is highest when both managers invest in CSR. Further, managers who invest in CSR are more sensitive to CSR disclosure information than managers who do not invest in CSR. Managers who invest in CSR are more cooperative when they receive a signal their partner also invested in CSR. Managers who do not invest in CSR do not attend to CSR disclosure information and are equally cooperative when partnered with a CSR investor or a non-CSR investor. Finally, when CSR investment is not disclosed, managers who invest in CSR are no more likely to cooperate than managers who do not invest in CSR. Although CSR is widespread, little is known about why managers invest in CSR or disclose CSR information. This study has implications for practitioners and academics on CSR by demonstrating a potential benefit of CSR investment and disclosure, mitigating relational risk in business collaborations.