Provided are an ultrasound imaging apparatus and a method of controlling the same. The ultrasound imaging apparatus includes: a probe configured to transmit ultrasound signals to an object and receive echo signals corresponding to the ultrasound signals; a display; and at least one processor configured to detect a reference region of a medical tool inserted into the object in an ultrasound image generated based on the echo signals, control the display to display at least one distance-indicating line arranged with respect to the reference region in the ultrasound image, and update a position of the at least one distance-indicating line according to movement of the medical tool.