The insertion of a double-j catheter in patients with urinary lithiasis is currently important because it reduces the chances of obstructive complications such as hydronephrosis and renal functional loss. The following case aims to show the patient evolution which presented the complete migration of the catheter to the renal pelvis and how it could complicate its prognosis. Placing a dual-catheter for treatment of lithiasis is a routine procedure in urology services but is not beyond complications during the process. Even with exhaustive complementary imaging exams, we must maintain a constant evaluation of the patient.