A magnetic resonance imaging apparatus includes a gradient coil, a transmission coil, an electrocardiographic signal detecting device detecting an electrocardiographic signal from a subject, a controlling device controlling the gradient coil and the transmission coil so that a pulse sequence including a preparation pulse and a data acquisition sequence for acquiring data from a subject utilizing a magnetic resonance phenomenon is repeatedly carried out, and a cardiac phase computing device computing the cardiac phase of the subject based on the electrocardiographic signal. The controlling device determines whether or not to re-acquire data once acquired from the subject based on the cardiac phase of the subject at an arbitrary time in a period during which the pulse sequence is carried out or the cardiac phase of the subject at a time after the pulse sequence is terminated.