An ultrasound observation device according to the present invention is an ultrasound observation device configured to generate Doppler information based on multiple sets of scan data acquired during sequential alternating scan in which ultrasound waves are sequentially transmitted in multiple depth directions and in which the ultrasound waves are repeatedly transmitted in this sequential order, and it includes: a calculation unit configured to perform comparison operation on first scan data acquired by transmitting the ultrasound waves in a depth direction for first scan during the sequential alternating scan and second scan data acquired by transmitting the ultrasound waves for a second time during the sequential alternating scan, the second scan data being acquired by transmitting the ultrasound waves in a depth direction identical to the depth direction for the first scan； and a sequential-alternating scan controller configured to control a repetition frequency based on a calculation result of the calculation unit.
