This book constitutes the refereed proceedings of the Third International Conference on Software Process, held in Vancouver, Canada, in May 2009 - colocated with ICSE 2009, the 31st International Conference on Software Engineering. The 33 revised full papers presented together with 3 invited papers were carefully reviewed and selected from 96 submissions. The papers are organized in topical sections on process management, process tools, process analysis, process simulation modeling, experience report, process metrics, and process modeling and representation.