Although ultrasound-guided axillary vein access (USGAVA) has proven to be a highly effective and safe method for cardiac electronic implantable device (CIED) lead placement, the collapsibility of the axillary vein (AV) during tidal breathing can lead to narrowing or complete collapse, posing a challenge for successful vein puncture and cannulation. We investigated the potential of the Valsalva maneuver (Vm) as a facilitating technique for USGAVA in this context. Out of 148 patients undergoing CIED implantation via USGAVA, 41 were asked to perform the Vm, because they were considered unsuitable for venipuncture due to a narrower AV diameter, as assessed by ultrasound (2.7 ± 1.7 mm vs. 9.1 ± 3.3 mm, p < 0.0001). Among them, 37 patients were able to perform the Vm correctly. Overall, the Vm resulted in an average increase in the AV diameter of 4.9 ± 3.4 mm (p < 0.001). USGAVA performed during the Vm was successful in 30 patients (81%), and no Vm-related complications were observed during the 30-day follow-up. In patients with unsuccessful USGAVA, the Vm resulted in a notably smaller increase in AV diameter (0.5 ± 0.3 mm vs. 6.0 ± 2.8 mm, p < 0.0001) compared to patients who achieved successful USGAVA, while performing the Vm. Therefore, the Vm is a feasible maneuver to enhance AV diameter and the success rate of USGAVA in most patients undergoing CIED implantation while maintaining safety.