Epicardial ablation complications are more frequent in patients with pre-existing pericardial adhesions. As opposed to the dry puncture technique, the coronary vein exit and CO2 insufflation (EpiCO2) technique allows diagnosis of pericardial adhesions prior to subxiphoid puncture. To evaluate the efficacy of the EpiCO2 technique in diagnosing pericardial adhesions prior to subxiphoid puncture. Following coronary vein exit, contrast was injected in the pericardial space and adhesions classified using our novel Brighton Adhesion Classification (BAC) into BAC-0 (no adhesions), BAC-1 (dispersed adhesions) and BAC-2 (dense adhesions extending to the entire assessed area(s)). CO2 insufflation allowed subclassification of BAC-1 adhesions into BAC-1a (not preventing epicardial access nor restricting catheter movement) and BAC-1b (either preventing epicardial access or significantly limiting catheter movement). Intentional coronary vein exit (right atrial appendage exit, in one case) was achieved in all 235 consecutive patients undergoing an epicardial ablation at our centre. A diagnosis of BAC-0 was made in 219 cases (93.2%), BAC-1a in 9 cases (3.8%), BAC-1b in 2 cases (0.9%) and BAC-2 in 5 cases (2.1%). This led to not attempting subxiphoid puncture in 6 cases (2.6%) and abandoning epicardial mapping due to limited catheter movement in 1 case (0.4%). Access-related complications occurred in 7 cases (3%) only in the BAC-0 group. The EpiCO2 technique allows assessment of the presence of pericardial adhesions prior to attempting subxiphoid puncture for epicardial access, which may lead to a reduction in the procedural complications within this subset of patients.