This book constitutes the refereed proceedings of the Third International Conference on Trust and Trustworthy Computing, TRUST 2010, held in Berlin, Germany, in June 2010. The 25 revised full papers and 6 short papers presented were carefully selected from numerous submissions. The papers are organized in a technical strand and a socio-economic strand and cover a broad range of concepts including trustworthy infrastructures, services, hardware, software, and protocols as well as social and economic aspects of the design, application, and usage of trusted computing.