Successful percutaneous nephrolithotomy (PCNL) relies on appropriate preoperative planning and optimal percutaneous access. CT has now become the standard imaging tool for PCNL. For percutaneous renal access, CT may be used for planning access, guiding access, and in the follow-up after access. In this review, we discuss the role of each aspect for percutaneous access in PCNL. In particular, we describe the technique for gaining access using CT, a valuable method in the difficult collecting system.