A biological information trend display device and method which allow the trend and an abnormal value of biological information to be checked with ease are provided. When a curve (50) showing the ST level in lead V3 exceeds the upper limit of a normal range, the part of the curve above the upper limit is displayed in an abnormal color “b” (red, for example). To indicate that the ST level derived from the lead V3 has exceeded the upper limit, a lead icon (32) in an upper part of the display screen is displayed in the abnormal color “b.”