The restless legs syndrome is a common disorder that encompasses an idiopathic form of genetic or unknown origin and symptomatic forms associated with many causes. Symptomatic forms occur during pregnancy and are coincident with uraemia, iron depletion, polyneuropathy, spinal disorders, and rheumatoid arthritis. For the hereditary forms, at least three gene loci, located on chromosomes 12, 14, and 9, have been traced so far. Prevalence in the general population is between 3% and 9%, increases with age, and is higher in women than in men. Treatment is needed only in the moderate to severe forms of the disorder and mostly in elderly people. Pathophysiology and treatment may be closely linked to the dopaminergic system and iron metabolism. Dopaminergic treatment with levodopa and dopamine agonists is the first choice in idiopathic restless legs syndrome, but augmentation and rebound should be monitored in long-term treatment. Various other drugs, such as opioids, gabapentin, and benzodiazepines, provide alternative treatment possibilities.