Objective <p>The study aims to compare the efficacy and safety of percutaneous nephrolithotomy (PCNL) and extracorporeal shock wave lithotripsy (ESWL) in treating renal pelvis calculus in infants.</p> Methodology <p>This randomized controlled trial took place in urology department from July 2023 to July 2024. No external funding was received for this research. A total of 84 infants aged 1–12&#xa0;months with renal pelvis calculus were randomly assigned to one of two groups: PCNL (Group A, <i>n</i> = 56) or ESWL (Group B, <i>n</i> = 28). Patients with severe comorbid illnesses or who had previously undergone renal pelvis calculus surgery were excluded. One month after therapy, stone clearance rates were examined using X-rays and ultrasonography. Postoperative complications included hematuria, urinary tract infections (UTIs), abdominal pain, and urinary tract blockage. The data was analyzed using SPSS with a statistical significance level of <i>p</i> &lt; 0.05.</p> Results <p>The study showed that the stone clearance rate was considerably higher in the PCNL group (92.9%) than in the ESWL group (53.6%) (<i>p</i> = 0.0001). The ESWL group had a greater incidence of postoperative complications, including urinary tract infections (14.3% vs. 0%, <i>p</i> = 0.004) and abdominal pain (10.7% vs. 0%, <i>p</i> = 0.01). Hematuria was more prevalent in the ESWL group, although not statistically significant (<i>p</i> = 0.07).</p> Conclusion <p>PCNL offers higher stone clearance rates than ESWL in infants with renal pelvis calculus. PCNL exhibited notably lower complications than ESWL.</p>