Objectives To assess the effects of a quality improvement (QI) team training intervention, by measuring the intervention fidelity and the compliance with a surgical site infection (SSI) bundle in the operating theatre (OT).Design Multicentre before–after study.Setting This study was performed in four Dutch hospitals.Intervention The QI team training intervention consisted of four sessions per hospital and stimulated participants to set culture norms and targets, identify barriers, and formulate management activities to improve compliance with four standard operating procedures (SOPs) of a SSI bundle in the OT. Participants were executive board members, top-level managers, leading clinicians and support staff. The four SOPs were: (1) reducing door movements; (2) preoperative antibiotic prophylaxis prescribing; (3) preoperative shaving; and (4) postoperative normothermia. Poisson and logistic regression analyses were performed to analyse the effect of the intervention on compliance with the individual SOPs (primary outcome measure) and on the influence of medical specialty, time of day the procedure took place and time in the OT (secondary outcome measures).Results Not all management layers were successfully involved during all sessions in the hospitals. Top-level managers were best represented in all hospitals, leading clinicians the least. The number of implemented improvement activities was low, ranging between 2 and 14. The team training intervention we developed was not associated with improvements in the compliance with the four SOP of the SSI bundle. Medical specialty, time of day, and time in OT were associated with median number of door movements, and preoperative antibiotic prophylaxis administration.Conclusion This study showed that after the QI team training intervention the overall compliance with the four SOPs did not improve. Minimal involvement of leading clinicians and a low number of self-initiated activities after the team training were important barriers for compliance.