There is provided a scan condition determining apparatus for a magnetic resonance imaging system comprising accepting means for accepting specification of a desired scan time; and searching means for searching for a second scan condition based on a first scan condition defined before the specification, by adjusting values of parameters affecting a scan time or a signal-to-noise ratio of signals obtained by a scan, said second scan condition being one with which the scan time approximates within an allowable range or matches the desired scan time, and besides, a lowest value of a relative signal-to-noise ratio of the signals approximates within an allowable range or matches a lowest value of the relative signal-to-noise ratio of the signals estimated based on the first scan condition. The parameters include, for example, any one of a number of times of addition, a y-axis direction resolution, a repetition time, and a number of data acquisition passes.