We meta-analyze the influence of various forms of embeddedness and proximity on interorganizational tie formation with a dataset that encompasses 256,529 ties from 73 studies. First, we uncover the unparalleled importance of relational embeddedness, while the influence of structural and positional embeddedness turns out to be highly dependent on the context. Second, we show that various forms of proximity positively influence tie formation and have unique explanatory power in addition to the embeddedness dimensions. Last, we explore to what extent these effects are contingent on the type of tie, resource munificence, status orientation, level of individuality, and intellectual property regimes. Our study introduces a preliminary contingency theory of interorganizational tie formation and provides directions for future research.