Sleep abnormalities are common and underrecognized in hospitalized patients. Sleep restriction is common and can have undesirable behavioral and physiologic effects. The general pattern of polysomnographic abnormalities observed in hospitalized patients is reduction in total sleep time, stages R (rapid eye movement), and N3 (slow wave) and increase in stage N1 percentage. Sleep is also fragmented with more arousals and awakenings. Multiple factors are responsible for sleep disruption in hospitalized patients and include environmental noise. Abnormalities in melatonin secretion leading to circadian rhythm abnormalities have also been noted. Hospitalized patients may also present with symptoms of obstructive sleep apnea. Protocols for sleep enhancement and management of obstructive sleep apnea are being implemented at various hospitals. Outcome data are awaited from these measures.