This book constitutes the refereed proceedings of the 28th International Conference on Applications and Theory of Petri Nets and Other Models of Concurrency, ICATPN 2007, held in Siedlce, Poland, in June 2007. The 22 revised full papers and 3 revised tool papers presented together with 5 invited papers were carefully reviewed and selected from a total of 70 submissions. All current issues on research and development in the area of Petri nets and modeling of concurrent systems are addressed, in particular system design and verification, analysis, synthesis, structure and behaviour of nets, net theory and relations, causality/partial order theory of concurrency, semantic Web, logical and algebraic calculi, symbolic net representation, tools for nets, experience reports and case studies, educational issues, higher-level net models, timed and stochastic nets, as well as standardization of nets.