Restless legs syndrome is a common, potentially disabling condition that affects about 10% to 15% of the general population and yet is often unrecognized and misdiagnosed. It is mainly diagnosed clinically and only rarely requires polysomnography. The condition is usually primary and treatable. First, however, secondary causes should be sought, especially iron deficiency and peripheral neuropathy, because when the source is an accompanying factor or condition, the syndrome may be curable. The most effective drugs are dopaminergic agents, clonazepam, opioids, gabapentin, and clonidine. Additional agents are available that may be beneficial as add-on or alternative therapy.