This paper examines barriers facing Thai SMEs, and identifies success factors for better participation in production networks. It utilizes information from a recent enterprise survey in 2009 covering clothing, automotive and electronics industries. Overall, SMEs perceived external barriers - business environment and tax, tariff and nontariff- as the most significant barriers. Key barriers for SMEs in the networks are difficulties in meeting product quality and standards, and in matching competitors’ prices, and lack of personnel for market expansion. Salient characteristics among SMEs participating actively in networks are their strong technological capabilities and proximity to ports or location within industrial estates. Strengthening absorptive capacities of SMEs, with special attention paid to technological development and its dissemination to SMEs, should be given higher priority.