A method of operating an ultrasound diagnosis apparatus includes: acquiring a plurality of frequency band images respectively having different frequency bands based on an ultrasound signal corresponding to an object； determining weights respectively for the plurality of frequency band images based on brightness levels of regions including the object in each of the plurality of frequency band images； synthesizing the plurality of frequency band images based on the weights for the plurality of frequency band images； and displaying a synthetic ultrasound image of the object, generated as a result of the synthesizing.
