An all-in-one mammography and breast ultrasonography apparatus is provided. The apparatus includes: a scanning table on which breasts are placed, the scanning table having a first axis aligned with a scanning direction of breasts and a second axis orthogonal to the first axis; an X-ray imaging device including an X-ray source arranged above the scanning table to generate X-rays for mammography and an X-ray flat panel detector arranged on the scanning table to detect the X-rays generated from the X-ray source; first and second ultrasound probes arranged on the scanning table so as to be adjacent to both ends of the X-ray flat panel detector to perform breast ultrasonography, the first and second ultrasound probes elongated along the second axis; and an orbital motion device installed on the scanning table to reciprocate the X-ray flat panel detector and the first and second ultrasound probes together along the first axis.