According to an embodiment, a moving object tracking device includes a memory having computer executable components stored therein; and a processor communicatively coupled to the memory. The processor is configured to perform acquiring a plurality of images; generating a plurality of pieces of tracking information indicating information obtained by tracking a moving object included in the images; generating first associated tracking information obtained by first association targeting the plurality of pieces of tracking information having a mutual time difference equal to or smaller than a threshold; generating second associated tracking information obtained by second association targeting the first associated tracking information and the tracking information, not associated by the first association, based on authentication information for identifying the moving object; and outputting the second associated tracking information.