An open nephrolithotomy is the removal of a stone from within the kidney and an open pyelolithotomy is the removal of a stone from within the renal pelvis, (the funnel shaped area for urine collection within the kidney) or from the ureter. Both operations are usually done through a 10-15cm incision in the flank (the side of the body between the ribs and the hip) which exposes the position of the stone.

Open stone surgery such as nephrolithotomy and pyelolithotomy are usually reserved for complicated, difficult stones which are causing blockage or ongoing symptoms such as pain and recurrent infection and are unable to be removed using less invasive treatments.