According to one embodiment, a monitoring system includes a monitoring terminal and a server. The monitoring terminal includes a detector, a tracking unit, a first selector, and a transmitter. The server includes a receiver, a second selector, a collation unit, and an output unit. The receiver receives a first best shot images from the monitoring terminal. The second selector performs second selection processing, as part of a predetermined selection processing other than a first selection processing, of selecting a second best shot image suitable for collation with a predetermined image from among the first best shot images. The collation unit performs collation processing of collating the second best shot image with the predetermined image. The output unit outputs a result of the collation processing.