A robot control device, abnormality diagnosis method, and non-transitory computer readable medium are provided. The robot control device (300) performs abnormality diagnosis of a robot body (200) including a motor (201) that rotates, from a starting angle position to a target angle position, a rotational shaft (204) for transmitting power to an arm (203) so that the arm performs a predetermined operation. The robot control device includes: a drive control unit (304) driving the motor so that the rotational shaft rotates from the starting angle position to the target angle position within a rotational speed range of the rotational shaft in which it is possible to detect a vibration component caused by an abnormality from among the vibration components generated along with the rotation of the rotational shaft; a vibration detection unit (305) detecting the vibration component; and a diagnosis unit performing abnormality diagnosis based on the detected vibration component.