An apparatus for estimating blood pressure is provided. According to one embodiment, the apparatus for estimating blood pressure may include a sensor configured to measure a bio-signal from a subject, and a processor configured to acquire, form the bio-signal, a first feature value associated with cardiac output (CO) and a second feature value associated with total peripheral resistance (TPR), determine whether a current mechanism of blood pressure change of the subject is a post-exercise hypotension mechanism based on the first feature value and the second feature value, and estimate blood pressure according to determination of whether the current mechanism is the post-exercise hypotension mechanism.