<p>This study aimed to evaluate the impact of costovertebral angle (CVA) width on the outcomes of percutaneous nephrolithotomy (PCNL), particularly regarding stone-free rates, bleeding, complication rates, and the need for additional interventions. A total of 181 patients who underwent prone PCNL between January 2018 and July 2024 at a single center were retrospectively analyzed. CVA was measured using preoperative standing direct urinary system X-rays. Patients were categorized into three groups based on CVA: &lt;45°, 45–55°, and &gt; 55°. Operative and postoperative parameters including hemoglobin/hematocrit decrease, transfusion requirement, complications (Modified Clavien-Dindo Classification), stone-free rate, and access type were evaluated and statistically analyzed. Hemoglobin and hematocrit decreases were significantly correlated with narrower CVAs (<i>p</i> = 0.041 for both). No significant relationship was observed between CVA and stone-free status, transfusion need, or complication rates. Although patients with CVA &lt; 45° had a higher rate of complications (38.9%) and greater blood loss, these findings did not reach statistical significance. Intercostal access, more frequently required in patients with narrow CVA, was associated with higher but not statistically significant complication rates. Narrow CVA may pose a greater challenge during PCNL due to limited nephroscope maneuverability, potentially increasing intraoperative bleeding. However, it does not significantly affect overall surgical success or complication rates. CVA can be considered a useful anatomical parameter during preoperative planning, especially when selecting the access route.</p>