The invention discloses a fraud detection system at a gam parlor. According to the invention, a novel system is provided for detecting fraud in games at a game parlor and for detecting mistakes or fraud during betting and settlement of chips. This fraud detection system detects fraud in games in which chips are collected and redeemed in accordance with win and loss results, and is provided with acamera (2) which images chips (9) housed a chip tray (17) of a dealer (5), an image analysis device (12) which analyzes images captured by the camera (2) and detects the value of the chips (9) housedin the chip tray (17), a card distributing device (13) which determines win and loss results in a game, and a control device (14) which detects fraud by comparing the win and loss results in the gamewith the value of the chips (9) stored in the chip tray (17) before and after chip collection and redemption.