Abstract Introduction Subclinical cardiac perforation, a known complication of cardiac implantable electronic device leads, occurs in 6–20% of cases. While leadless pacemakers are advised to be placed in the septum to mitigate perforation risk, limited studies exist on lead positioning and perforation incidence. Objectives This retrospective observational study aimed to assess leadless pacemaker lead positions, determine the incidence of subclinical cardiac perforation, and evaluate associated prognoses through computed tomography (CT) in post-implantation patients. Methods Thirty-one patients underwent CT after leadless pacemaker implantation. Two cardiologists and a radiologist analyzed CT scans to categorize lead positions (septum, free wall, or septum-free wall junction) and identify subclinical perforation (defined as tine transversal beyond the outer myocardial contour without symptoms, hemodynamic instability, or pacemaker issues). Results Mean age at implantation was 70.5 ± 12.7 years; 35.5% were male, and 41.9% had atrial fibrillation. Twenty patients (64.5%) were on anticoagulants or antiplatelet agents. Twenty-four patients (77.4%) were positioned at the septum-free wall junction. Subclinical perforation occurred in 12 patients (38.7%), with a higher proportion in patients on non-vitamin K antagonist oral anticoagulants. Two patients had moderate amount of pericardial effusion; the remaining ten with subclinical perforation were stable during follow-up. Conclusions The most common leadless pacemaker implantation site was the septum-free wall junction with 38.7% of subclinical perforation.