The incidence of upper pole calculi is 15% of all caliceal calculi. The management of such calculi has been simplified since the advent of extracorporeal shockwave lithotripsy (SWL). In our experience, however, there is a subset of upper pole caliceal calculi wherein certain features can render SWL less than adequate treatment, namely diameter >1.5 cm, narrowing of the caliceal infundibulum, either singly or combined, and morbid obesity. In such instances, percutaneous nephrolithotomy (PCNL) is indicated. Percutaneous access to an upper pole calix can be difficult by a subcostal track. The supracostal 12th rib approach provides direct and efficient access to an upper pole calix and is ideally suited for upper pole calculi. Twenty-one patients with large or complex upper pole calculi were treated by supracostal PCNL. The maximum diameter of the calculi ranged from 7 to 40 mm. Eight were branched (staghorn). There was one horseshoe kidney, and calculi were bilaterally represented in another patient. Two patients were morbidly obese. All procedures were performed in one stage under general anesthesia. Following cystoscopy and ureteral catheterization, the upper pole calix was accessed directly with the aid of C-arm fluoroscopy and retrograde ureteral contrast injection. The percutaneous tract was dilated to a maximum of 26 F, a working sheath was inserted, and the calculi were extracted after ultrasonic or pneumatic fragmentation. One patient required secondary SWL for residual fragments. There were no intrathoracic complications, and blood loss was minimal. Large or complex upper pole caliceal calculi, particularly in the morbidly obese, can be treated effectively by PCNL using supracostal percutaneous access.