A survey of new product development (NPD) managers finds both a linear, positive relationship between managerial guanxi and new product speed to market and an inverted U-shaped relationship between managerial guanxi and new product innovativeness. In addition, both transaction-specific investments (TSIs) and relationship commitment have a positive moderating impact on the relationship between managerial guanxi and new product speed to market. However, TSIs increase the damaging effect of managerial guanxi on new product innovativeness, whereas relationship commitment reduces such an effect. The results from this study can help business practitioners use guanxi to improve NPD performance under different contexts of inter-firm relationships.