Renal stones (nephrolithiasis) are a relatively common problem and a frequent Emergency Department (ED) diagnosis in patients who present with acute flank/abdominal pain. The goal of this topic review is to provide physicians with an evidence-based diagnostic approach for the evaluation and management of patients with nephrolithiasis. Unenhanced helical CT scan of the abdomen and pelvis should be performed on all patients with their first episode of acute flank pain and suspected renal colic. It is considered the optimal diagnostic test to confirm a urinary stone in a patient with flank pain. Pain management can be achieved by using NSAIDs, opioids or a combination of both. Several factors will help you determine if emergent urology evaluation is warranted; size and location of renal calculi, persistence of colic pain, impaired renal function and signs of infection.