A medical image diagnosing support method is provided that includes a site region extracting step for obtaining a tomographic image which is picked up by a medical diagnostic imaging apparatus and extracting a predetermined site region from the obtained tomographic image, a first region extracting step for extracting a first lesion candidate region from the site region based on pixel values of the site region extracted in the predetermined site region extracting step, a second region extracting step for extracting a second lesion candidate region from the site region based on a distribution of the pixel values of the site region extracted in the predetermined site region extracting step, and a region correcting step for correcting the first lesion candidate region extracted in the first region extracting step by using the second lesion candidate region extracted in the second region extracting step.