['Unenhanced multidetector computed tomography (UMDCT) is well established as the procedure of choice for radiologic evaluation of patients with renal colic. The procedure has both clinical and financial consequences for departments of surgery and radiology. However, the financial effect outside the radiology department is poorly elucidated.', 'To evaluate the financial consequences outside of the radiology department, a retrospective study comparing the ward occupation of patients examined with UMDCT to that of intravenous urography (IVU) was performed.', 'A total of 594 consecutive patients were admitted for renal colic during two 6-month periods. One hundred seventy-three consecutive patients were examined with IVU in 2000 and 421 with UMDCT in 2005. The only difference between the two groups was the imaging procedure. The duration of hospital stay and pathology findings were registered.', 'In 50% of the patients undergoing UMDCT, a stone was found; a stone was found or suspected in 40% of patients undergoing IVU. Patients undergoing IVU stayed significantly longer in the ward than patients examined by UMDCT (P<0.0001). The new procedure (UMDCT) saved the hospital USD 265,000 every 6 months compared to the use of IVU.'] Does unenhanced computed tomography in acute renal colic reduce cost outside radiology department?