A watching assistance system that assists watching over a subject on a bed, the watching assistance system includes: a detector configured to detect a position of a predetermined region of the subject from the image captured by an imaging device； a determination unit configured to determine whether the subject raises oneself up based on the position at which the predetermined region of the subject is detected； and an output unit configured to provide notification when the determination unit determines that the subject raises oneself up. Based on a bed region in the image, a lying region is set to an existing range of a predetermined region at a lying time, and a raising-up region is set to an existing range of the predetermined region at a raising-up time. The lying region and the raising-up region are disposed at an interval. The determination unit determines that the subject raises oneself up when a condition that predetermined region of the subject is detected in the raising-up region after the predetermined region of the subject is detected in the lying region is satisfied.
