A portable electronic device with scroll wheel control module includes a housing (20), a display (212) and two scroll wheel mechanisms (41,42). Two side walls (220) of the housing having a slot (222) defined therein. Each scroll wheel mechanism includes a main wheel (432), a circuit board (45) a touch switch (47) and a sensing apparatus (46). The main wheel has gratings (4322) defined therein and partially extends out from the slot of the side wall. The touch switch is below the main wheel and is positioned on a circuit board. The sensing apparatus includes a light source (462) configured for emitting light and a light sensing element (464) configured for receiving light from the gratings of the main wheel and producing a pulse signal. When the main wheel is pressed down, the touch switch produces an electronic signal.