Provided are a medical imaging apparatus and a method of generating a medical image that are capable of generating a Doppler image by using a Doppler effect as well as an ultrasound image. The method of generating a medical image includes: acquiring received signals; acquiring an ultrasound image and displaying the acquired ultrasound image; acquiring a Doppler signal corresponding to a sample volume set on the ultrasound image; generating a Doppler image based on the Doppler signal and displaying the generated Doppler image; calculating at least one selected from an average magnitude, a maximum value, and a minimum value of the Doppler signal; and changing image displaying mode by suspending the displaying of the Doppler image and updating the ultrasound image, in response to the at least one selected from the average magnitude, the maximum value, and the minimum value is less than or equal to a threshold value thereof.