Participation in organizational decision-making has received considerable attention from scholars. Beyond the perspectives proposed in past studies, we offer a new account, based upon a communication perspective, to explain why and when participation in decision-making can influence job satisfaction. Drawing from social capital theory, we examine whether communication openness mediates the relationship between participation in decision-making and job satisfaction. We also investigate how information adequacy moderates this mediated process. Results from a sample of 184 employees in China showed that the four-factor model was the best fitting solution (CFI = .91, GFI = .90, RMSEA = .09). The analyses indicated that employees’ participation in decision-making positively affected their job satisfaction (β = .32, p < .001), and the effect was mediated by communication openness (direct effect became non-significant when communication openness was included: β = .06, n.s.). Results also found that decision-making information adequacy positively moderated the relationship between participation in decision-making and communication openness (β = .13, p < .05). Thus, open communication and the free flow of information within organizations should be encouraged.