OBJECTIVE: Since the introduction of percutaneous nephrolithotomy (PCNL), many changes have been added regarding the entrance to pyelocalyceal system such as insertion of the needle pointed to an opaque stone as a guided landmark. We aim at comparing the outcomes of managing renal calculi with and without retrograde pyelography. MATERIALS AND METHODS: In a randomized clinical trial, 55 cases with opaque renal calculi candidates for PCNL with stone in one calyce, in the pelvis or both in one calyce and the pelvis simultaneously were included in a nine-month study. They were randomized into 2 groups, noncatheterized (n = 28) and catheterized (n = 27), called intervention and control groups, respectively. RESULTS: The 2 groups had similar distributions regarding gender, age, duration of operation, length of hospital stay, past history of any surgical procedures on kidney, and stone size. Outcome (residual stone based on aforementioned management) was evaluated with plain X-ray on the morning following the operation. Postoperative hemoglobin decrease was significantly higher in controls than in the intervention group (p < 0.001) (with no clinical significance). No difference in outcome, postoperative fever, duration of surgery, duration of hospital stay and radiation exposure was observed between the 2 groups. CONCLUSION: Our findings showed no differences in major clinical outcomes between the 2 groups (with and without catheter insertion for retrograde pyelography).