Despite the prevalent role of guanxi in conducting business in Chinese, it is unclear whether interpersonal guanxi fosters interfirm trust. Taking a contingency approach, this study examines how institutional (government–market relationship and Buddhism influence) and individual (relative role performance and the span of partner control) factors moderate the association between interpersonal guanxi and interfirm trust. Based on a paired survey between salespersons and sales managers and two secondary datasets, this study finds that interpersonal guanxi is positively associated with interfirm trust. (...) Moreover, this positive effect is stronger when firms operate in regions with strong government–market relationships and strong Buddhism influence. In addition, the positive relationship is weaker when guanxi resides in boundary spanners who have relatively high role performance, but becomes stronger when boundary spanners have a broad span of partner control. These findings highlight the situations in which guanxi at an interpersonal level is more or less likely to foster interfirm trust. (shrink)