Abstract: An overflow detection device is capable of determining whether liquid outside of the device has reached a predetermined level associated with an overflow condition. A container has a closed end and a capped end opposite the closed end. The container has an enclosing wall which extends from the closed end to an open or capped end to define an interior region. A hole or holes are formed in the enclosing wall. The holes are positioned a predetermined distance from the closed end of the container. The holes permit flow of the liquid into the interior region of the container when the liquid level reaches the predetermined level. A flotation piece is situated in the interior region of the container. The flotation piece is capable of floating on liquid which has flowed into the interior region. A visual indicator piece is coupled to or integral with the flotation piece. The visual indicator piece rises with the flotation piece when the level of the liquid contained in the interior region of the container rises.