Abstract Aims No prior study has been adequately powered to evaluate real-world safety outcomes in those receiving adjunctive ablation lesions beyond pulmonary vein isolation (PVI). We sought to evaluate characteristics and in-hospital complications among patients undergoing PVI with and without adjunctive lesions. Methods and results Patients in the National Cardiovascular Data Registry AFib Ablation Registry undergoing first-time atrial fibrillation (AF) ablation between 2016 and 2020 were identified and stratified into paroxysmal (PAF) and persistent AF, and separated into PVI only, PVI + cavotricuspid isthmus (CTI) ablation, and PVI + adjunctive (superior vena cava isolation, coronary sinus, vein of Marshall, atypical atrial flutter lines, other). Adjusted odds of adverse events were calculated using multivariable logistic regression. A total of 50 937 patients [PAF: 30 551 (60%), persistent AF: 20 386 (40%)] were included. Among those with PAF, there were no differences in the adjusted odds of complications between PVI + CTI or PVI + adjunctive when compared with PVI only. Among persistent AF, PVI + adjunctive was associated with a higher risk of any complication [3.0 vs. 4.5%, odds ratio (OR) 1.30, 95% confidence interval (CI) 1.07–1.58] and major complication (0.8 vs. 1.4%, OR 1.56, 95% CI 1.10–2.21), while no differences were observed in PVI + CTI compared with PVI only. Overall, there was high heterogeneity in adjunctive lesion type, and those receiving adjunctive lesions had a higher comorbidity burden. Conclusion Additional CTI ablation was common without an increased risk of complications. Adjunctive lesions other than CTI are commonly performed in those with more comorbidities and were associated with an increased risk of complications in persistent AF, although the current analysis is limited by high heterogeneity in adjunctive lesion set type.