A stage determination support system according to an embodiment includes devices. The storage device stores a plurality of kinds of functional images of a subject. The first determination device determines a degree of each of a plurality of kinds of analysis indices relating to a disease, based on at least the functional images among functional images and the morphological images. The second determination device determines, based on each of determination results and a predetermined stage determination rule, a stage corresponding to the determination result with respect to each of the analysis indices. The calculation device calculates, with respect to each of the stages, a value indicative of a possibility that the disease corresponds to the stage, based on each of determination results.