Asynchronous online discussions (AODs) are a central component of online courses and have been widely implemented in case-based instruction (CBI). In online CBI, AODs offer learners a medium for making sense of complex problems, as they consider case topics collaboratively with peers and facilitators. Therefore, learners' interactions with others have the potential to impact the overall effectiveness of the method, and specifically, participating in AODS during CBI may help learners develop problem-solving skills. However, little research has considered how learners' interaction patterns in an AOD relate to the development of problem-solving skills during CBI. We used social network analysis (SNA) to consider the relationship between social interactions and learners' problem-solving skills, as it offers a way to consider the structure of learners' social interactions. We found that the number of posts, replies, and connections learners made in course discussions were related to problem-solving performance measured both in case analyses and overall course grade.