To provide a bed fall detection system and a bed device, for determining fall possibility that a user on a bed falls from the bed, or a fall fact that the user has fallen from the bed with high determination accuracy.

This bed fall detection system includes: a sensor group 4 comprising a plurality (M pieces) of sensors 3 provided in the bed 1 distributively in positions wherein the user lies down on the bed 1, each detecting a physical quantity generated from the user to detect presence of the user; and a determination means executing determination processing for determining the fall possibility that the user falls from the bed 1, or the fall fact that the user has fallen from the bed 1 based on the positions of the bed 1 of an upper sensor group 40 comprising sensors each having high output value of the sensor group 4 in plane coordinates.