Nocturia is a very common yet a highly underreported entity. Recently, there has been an increasing interest in nocturia because of its association with serious adverse health conditions such as diabetes, heart disease, elevated BMI, and mortality. Frequency volume charts are the cornerstone of initial assessment and are pivotal in determining the type of nocturia and associated causes. The diagnostic evaluation is aimed at clarifying the underlying cause: sleep disturbances, reduced bladder capacity (functional or extrinsic), and increased urine production (nocturnal or daily). Obstructive sleep apnea is an important cause of nocturnal polyuria and should always been considered. Management is focused on treating the underlying cause; a range of behavioral and pharmacologic options are available.