A monitoring system includes a plurality of image-capturing apparatuses each including an event detector that executes on a corresponding captured image at least one of a plurality of processing algorithms for detection of a monitor event, and a transmission controller that outputs to a network only a processing result of the executed processing algorithm when a monitor event is not detected and that outputs to the network at least the captured image when a monitor event is detected; and a management apparatus managing the plurality of image-capturing apparatuses via the network and including an event determination unit that determines occurrence of a monitor event in accordance with the received processing result and a record controller that records the received captured image.