We analyze partner selection decisions in coopetition for innovation. We study how much risk (related to competition) small and large firms are willing to accept to realize the potential benefits of cooperating with a competitor. We use a choice-based conjoint analysis to examine the importance of and trade-off between seven attributes associated with competitors as partners. We show that the level of competition is the most important attribute for small and large firms. SMEs are willing to partner with a competitor if that partnership can reduce costs and the time-to-market, while large firms place more value on the learning opportunities.