Intermittent exotropia is often an early stage of permanent exotropia, and parents are often confused about whether and when to operate for this type of strabismus, because the strabismus is sporadic and they are afraid that if they operate now, they will have sometimes internal strabismus. In fact, the timing of surgery for intermittent exotropia is based on four factors: (1) The degree of intermittent episodes (including the frequency and duration of episodes). (2) The degree of strabismus examined by the surgeon, the soundness of monocular function in both eyes, and whether amblyopia is combined. (3) Children with occasional episodes, short duration of each episode, control of orthostasis once reminded, relatively mild degree of strabismus on doctor’s examination, and sound monocular function of both eyes can be closely followed and temporarily not operated, otherwise surgery is required. (4) Children with combined amblyopia should be treated for amblyopia first, otherwise the eye position is not easily maintained after surgery.