BACKGROUND AND AIMS: An insufficient number of premature ventricular complexes (PVCs) during catheter ablation (CA) may prohibit adequate mapping of the site of origin. Parameters to predict this situation have not been established. Our objective was to quantify the association between preprocedural information and the probability of a sufficient number of PVCs for adequate mapping and successful CA. METHODS: Clinical characteristics and results from examinations and procedural data were collected retrospectively from health journals for patients admitted for CA of PVCs from 2011 to 2020. RESULTS: In total, 46 of 332 patients (14%) had an insufficient number of PVCs to enable adequate electroanatomical mapping. Patients with a sufficient number of PVCs had nominally more PVCs in the 24-h electrocardiogram (ECG), with a strong statistical trend [16,007 (6,509-26,205) vs. 8,332 (3,066-20,974), CONCLUSION: The number of PVCs in a 24-h ECG was moderately associated with the presence of a sufficient number of PVCs to perform electroanatomical mapping during CA. The presence of more PVCs in the preprocedural 24-h ECG was associated with the use of activation mapping as the sole mapping strategy.