The objective of this chapter is to introduce the restless leg syndrome (RLS). RLS, a sleep related movement disorder is an often missed or misdiagnosed entity in our practice. It affects the quality of the sleep of the individual and indirectly affects the functioning ability of the patient. Restless legs syndrome is a sleep-wake cycle disorder presenting with dysesthesia especially in the lower limbs that causes an urge to move the limbs which has a typical nocturnal worsening. The adverse effect associated with RLS includes poor sleep quality, impaired day time functioning, metabolic complications, neuropsychiatric disturbances. This chapter covers the diagnostic criteria of RLS, classification of RLS, genetics of RLS, signs and symptoms of RLS, RLS in women and children, pathophysiology of RLS, differential diagnosis of RLS, and management of RLS.