Firms are increasingly introducing enterprise social media (ESM) technologies to nurture the virtual community of practice, offering a prospect for collaborative problem-solving (CPS) within organizations. Based on a unique dataset including 10101 actual problem-solving scenarios across 519 ESM groups, our objective is to identify the relationships between many social factors and the occurrence of CPS by drawing on different social theories. Via multilevel logistic regression, we found that the quality and decentralized degree of social interactions in an ESM group can increase the likelihood of CPS; one user's social similarity with other members of the group and the user's user classes are positively related to the likelihood of CPS. Finally, social ties' strength between the user and other members in the ESM group has a U-shaped association with the likelihood of CPS. These findings can provide companies with meaningful implications for using ESM sites to support CPS. INDEX TERMS collaborative problem-solving, enterprise social media, virtual group, social influence, multilevel logistic modeling.