A medical monitor is a medical device that displays a patient's vital signs continually, without using paper. In critical care units of hospitals, it allows continuous supervision of a patient without continuous attendance. This improves patient care.

Monitors resemble oscilloscopes, or computer monitors and use superficially similar technology. However medical monitors have been safety engineered so that failures are either apparent, or unimportant.

Additionally, some monitors (e.g. ECG and EEG) actually touch patients, and are electrical. There are strict limits on how much current and voltage they can apply when the unit fails or becomes wet.