In an ultrasound diagnosis apparatus according to an embodiment, processing circuitry obtains volume data corresponding to at least one cardiac cycle and being taken of a region including the right ventricle of a patient. The processing circuitry estimates motion information of a tissue in the region by using the volume data. The processing circuitry calculates information including at least one selected from between wall motion information and volume information related to the right ventricle, on the basis of the motion information of the tissue. The processing circuitry outputs the calculated information. The processing circuitry corrects first motion information of the right ventricular outflow tract, which is an outflow tract of the right ventricle, by using second motion information of a site that is positioned in the vicinity of the right ventricular outflow tract and exhibits motion similar to that of the right ventricular outflow tract.