A portable electronic device includes superposed base and sliding housings, a pair of guide units and a pair of slide rails that cooperate with each other to permit sliding movement of the sliding housing relative to the base housing along a sliding direction between closed and open positions, and a pair of correction mechanisms respectively adjacent to the slide rails and each including at least two push-back members. When the slide rails deviate from the sliding direction, the push-back members can push back the slide rails to a position parallel to the sliding direction so that the slide rails can slide smoothly relative to the guide units.