Abstract Purpose Definitive fascial closure is an essential treatment objective after open abdomen treatment and mitigates morbidity and mortality. There is a paucity of evidence on factors that promote or prevent definitive fascial closure. Methods A multi-center multivariable analysis of data from the Open Abdomen Route of the European Hernia Society included all cases between 1 May 2015 and 31 December 2019. Different treatment elements, i.e. the use of a visceral protective layer, negative-pressure wound therapy and dynamic closure techniques, as well as patient characteristics were included in the multivariable analysis. The study was registered in the International Clinical Trials Registry Platform via the German Registry for Clinical Trials (DRK00021719). Results Data were included from 630 patients from eleven surgical departments in six European countries. Indications for OAT were peritonitis (46%), abdominal compartment syndrome (20.5%), burst abdomen (11.3%), abdominal trauma (9%), and other conditions (13.2%). The overall definitive fascial closure rate was 57.5% in the intention-to-treat analysis and 71% in the per-protocol analysis. The multivariable analysis showed a positive correlation of negative-pressure wound therapy (odds ratio: 2.496, p < 0.001) and dynamic closure techniques (odds ratio: 2.687, p < 0.001) with fascial closure and a negative correlation of intra-abdominal contamination (odds ratio: 0.630, p = 0.029) and the number of surgical procedures before OAT (odds ratio: 0.740, p = 0.005) with DFC. Conclusion The clinical course and prognosis of open abdomen treatment can significantly be improved by the use of treatment elements such as negative-pressure wound therapy and dynamic closure techniques, which are associated with definitive fascial closure.