A medical diagnostic imaging apparatus is provided that is capable of accurately tracking motions of a moving organ that moves periodically over a plurality of periods. The medical diagnostic imaging apparatus includes a matching computation unit for performing a matching computation between a template extracted containing a tracking point on one image and another image, and a template extracting unit for extracting, from the other image, a region correlated with the template as a template of the other image by the matching computation, whereby a movement of the tracking point is tracked based on the extracted template. The template extracting unit extracts, as a key template, a region containing one or more tracking points set on an image at least one time phase within a motion cycle of the moving organ. The matching computation unit performs the matching computation using the key template in the vicinity of the time phase at which the key template is extracted.
