The gain to stockholders from mergers is well documented. However, there is little evidence as to whether the source of the gain is due to synergy or management displacement. Merger is just one of an almost limitless variety of ways in which firms combine resources to accomplish some objective. A joint venture is another. In addition to being of interest as an independent phenomenon, because the original managements of the parent firms remain intact under a joint venture, investigation of wealth gains from joint ventures provides an opportunity to isolate the management displacement hypothesis from the synergy hypothesis as the source of gains in corporate combinations. Our results are 1) there are significant wealth gains from joint ventures, 2) the smaller partner earns a larger excess rate of return while the dollar gains are more equally divided, and 3) the gains, scaled by resources committed, yield “premiums” similar to those in mergers. We are inclined to interpret our results as supportive of the synergy hypothesis as the source of gain from corporate combinations.