A reciprocating pencil sharpener has a stationary member, a cutter and a ratchet mechanism. The cutter includes a blade secured to a blade holder. The ratchet mechanism is mounted between the stationary member and the cutter and allows the cutter to rotate relative to the stationary member in one direction only. When a user desires to sharpen a pencil, the user can keep the pencil in the hand and rotate the pencil in reciprocating rotation, thus obtaining the sharpened point of the pencil. Consequently, it is convenient for the user to apply a rotational force and a high efficiency of sharpening operation is achieved.