Salt-reduction guidance to hypertensive patients should be performed by evaluating salt intake of the individuals. However, each method to assess salt intake has both merits and limitations. Therefore, evaluation methods must be selected in accordance with the subject and facility's environment. In special facilities for hypertension treatment, measurement of sodium (Na) excretion with 24-h pooled urine or a survey on dietary contents by dietitians is recommended. In medical facilities in general, measurement of the levels of Na and creatinine (Cr) using second urine samples after waking-up or spot urine samples is recommended. The reliability of this method improves by using formulae including a formula to estimate 24-h Cr excretion. A method to estimate salt intake based on the Na excretion per gram Cr using the Na/Cr ratio in spot urine is simple, but not reliable. The method to estimate the daily excretion of salt from nighttime urine using an electronic salt sensor installed with a formula is recommended to hypertensive patients. Although its reliability is not high, patients themselves can measure this parameter simply at home and thus useful for monitoring salt intake and may intensify consciousness regarding salt reduction. Using these methods, salt intake (excretion) should be evaluated, and salt-reduction guidance targeting <6 g (Na: 100 mmol) per day should be conducted in the management of hypertension.