A similar case searching apparatus comprising: a weight determining unit which determines the weight to each of feature quantities extracted from an interpretation target image, based on predetermined two-data correlation information defining the correlation between the feature quantity and one of at least one image interpretation item and a disease name both included in an image interpretation report of a medical image included in a case data item registered in a case database, such that the weight is larger as the correlation is higher; and a similar case searching unit which searches for a similar case data item including a similar image, by weighting, using the weight, each image feature quantity in a first set extracted from the interpretation target image and a corresponding one of the image feature quantities in a second set extracted from the medical image, and comparing the weighted first set and the weighted second set.