This study examines the role of inter-firm partnership ties in the entry into new market domains in the empirical context of the U.S. venture capital (VC) industry over a 23-year period. By adopting an open-system theoretical perspective and drawing on theories of interorganizational networks and organizational learning, we suggest that ties to partners influence a focal firm’s choice of new markets to enter. New market entry is directed toward the markets in which VC firms’ partners are present. Alternative avenues of uncertainty reduction in new markets moderate this effect, while firms’ lower tolerance for uncertainty increases it. Specifically, market relatedness, firm experience, and network closure dampen the effect of network ties, while the early-stage investment orientation of VC firms amplifies it.