A similar case searching apparatus includes: an image feature quantity extracting unit which extracts image feature quantities from an interpretation target image; a reference expression extracting unit which extracts a reference expression from a description related to a second test in a target image interpretation report; a weight determining unit which determines, for each image feature quantity, a weight which is larger as the correlation between the image feature quantity and the reference expression is higher, based on two-data correlation information; and a similar case searching unit which searches a case database for a similar case data item including a medical image similar to the interpretation target image, by weighting the image feature quantity extracted from the interpretation target image and a corresponding image feature quantity extracted from the medical image and comparing the weighted image feature quantities.