Background Left atrial appendage closure (LAAC) is an established therapeutic strategy to prevent ischemic stroke in selected patients with atrial fibrillation. However, residual peridevice leaks (PDLs) post-LAAC remain a critical concern.Objectives This study sought to assess the clinical impact of Watchman FLX device overcompression.Methods Data on consecutive patients undergoing a transesophageal echocardiography (TEE)-guided LAAC between 2020 and 2023 in 2 high-LAAC volume centers were collected and patients with a device compression higher (overcompression group) or lower (normal compression group) than 30% as evaluated by procedural TEE were compared in terms of procedural complications, composite of cardiovascular death, ischemic stroke, or systemic embolism, and PDL at TEE follow-up.Results This study included 61 overcompression and 175 normal compression patients. Baseline and procedural characteristics did not differ between the 2 groups. Both composite of procedural complications (1.6% vs 1.7%; P = 0.968) and of cardiovascular death, ischemic stroke, or systemic embolism during follow-up (9.8% vs 12%; P = 0.971) did not significantly differ between the 2 groups. At 2-month TEE follow-up, the rate of residual PDL was significantly lower in the overcompression group (8.2% vs 32.6%; P < 0.001). At the multivariate analysis, the device compression rate was the only variable independently associated to risk of PDL at TEE follow-up (adjusted OR: 0.935; 95% CI: 0.927-0.948; P = 0.003).Conclusions In this dual-center cohort of TEE-guided LAAC, the overcompression group was independently associated to a higher rate of LAA occlusion at TEE follow-up.