This volume contains the proceedings of the 15th International Conference on Application and Theory of Petri Nets, held at Zaragoza, Spain in June 1994. The annual Petri net conferences are usually visited by some 150 - 200 Petri net experts coming from academia and industry all over the world. The 28 full papers were selected out of in total 85 submissions from 18 countries. Together with the 3 invited contributions, these papers give a state-of-the-art report on all relevant aspects of Petri nets.