PROBLEM TO BE SOLVED: To provide a medical image diagnostic apparatus capable of reducing a visual axis movement and an operation of a user when setting a degree of transparency of each area included in volume data, and to provide a medical image processing method.SOLUTION: The medical image diagnostic apparatus includes a first designation unit, a setup unit, and a first display control unit. The first designation unit, according to an input by an operation of an input unit, designates a position in a three-dimensional image displayed on a display unit that displays the three-dimensional image as a rendering result of volume data including a first area and a second area covering at least a part of the first area. The setup unit variably sets a degree of transparency of the second area according to movement of the position designated by the first designation unit. The first display control unit executes the rendering of the volume data on the basis of the degree of transparency set by the setup unit and executes a control for displaying the three-dimensional image obtained by the rendering, on a display unit.
