These are the proceedings of the International Workshop on Petri Nets and Software Engineering (PNSE'2023) to be held at June 27, 2023. The workshop is co-located with 44th International Conference on Application and Theory of Petri Nets and Concurrency (PETRI NETS 2023) in Lisbon, Portugal. The workshop emphasizes on the impact of software engineering in general and its development based on Petri nets. Therefore we have especially invited contributions that work on subjects that could be relevant for Petri nets, their application, supporting tools, etc. Results on other formalisms or semi-formal techniques are highly welcome. More information about the workshop can be found at: http://www.pnse.de/ As some of the previous editions of PNSE had to be organised as virtual meetings we are very happy that this time the workshop could be organised in the good old-fashioned way. Overall we received 18 contributions for these proceedings. Each paper was reviewed by at least three referees. During the reviewing process the program comittee selected 10 contributions for publication. The workshop was organised in sessions with long and short presentations. The workshop also has its poster session for ongoing work. The proceedings also contain the extended abstracts for the accepted poster contributions. We are glad that Wojciech Penczek accepted our invitation to give a talk about Model Checking of Strategic Timed Temporal Logics. The international program committee of PNSE'23 was supported by the valued work of Lukasz Mikulski, Mathias Pfei er, Abbas Rahimi, and Max Stachon as additional reviewers. Their valuable work is highly appreciated. Furthermore, we would like to thank our colleagues in the PC and the local organization team in Lisbon for their support.