An auto-released hinge for a mobile phone has a barrel with two open ends. The barrel has a first flange formed inside the barrel. A first spiral slot is defined in the first flange. Two stop slots are defined in the barrel and two second spiral slots are defined between the respective stop slots and the first flange. A pintle is rotatably received in the barrel, and has a first end extending out from the barrel and a second flange formed adjacent a second end of the pintle. A protrusion is formed at an outer periphery of the pintle and received in the first spiral slot. Two ridges are formed adjacent the second flange and respectively blocked in the stop slots. A resilient member is provided outside the second end of the pintle. A fastener is positioned in the barrel to fasten the pintle and the resilient member.