BACKGROUND The horseshoe kidney is the most frequent renal anomaly, with a prevalence of 0.25% and a male to female ratio of 3:1. Although the pathogenesis remains controversial, the consequences of the impaired urinary drainage are well known: up to two third of patients present with urinary stasis, infection and urolithiasis. Percutaneous nephrolithotomy (PCNL) is a successful procedure for urolithiasis in horseshoe kidneys. METHODS A 9-year-old patient with a 4-cm stone associated with horseshoe kidney underwent Percutaneous nephrolithotomy (PCNL). During the procedure, a flexible uretheroscopy was performed in order to obtain a complete vision and an optimal management of the procedure. RESULTS At the end of the procedure, the patient was stone-free. We reported no hemorrhagic complications, no pain and no infection. The patient was discharged after 48 hours. CONCLUSIONS The procedure is safe and effective, as long as the surgeon pays attention to the recommendations below.