An ice-making device for a refrigerator including a duct providing a cold air flow path under an ice tray in which water turns into ice pieces. Uneven portions extending in a direction differing from a flow direction of cold air are formed at a lower surface of the ice tray. The duct may have a wavy surface. The surface features of the ice tray and the duct can advantageously increase contact area and contact time between cold air and the ice tray, thereby increasing the heat exchange efficiency between cold air and water contained in the ice tray.