In an ultrasonic diagnostic apparatus, a scan controller inputs a trigger signal corresponding to heartbeat period, scans an ultrasonic beam such that a particular diagnostic region of a body under examination is scanned with the ultrasonic beam a plurality of times in response to each trigger signal, and controls the scan repetition period by controlling the pulse repetition period of the transmission pulse. An image generation unit generates an image corresponding to each of the pulse repetition periods. The scan controller controls the pulse repletion period such that an integral multiple of the scan repetition period is equal to a reference value determined based on the period of the trigger signal.
