A magnetic resonance imaging apparatus collects raw data about a subject in a synchronized manner with an electrocardiographic signal of the subject. An Electrocardiogram (ECG) gating unit detects an irregular synchronization interval with respect to the electrocardiographic signal. When the ECG gating unit detects an irregular synchronization interval, a real-time sequencer controls a gradient magnetic-field power source, a transmitting unit, and the like so as to reacquire raw data that is acquired during the irregular synchronization interval.