Ectropion, or eyelid eversion, is the most common form of eyelid malposition. By impairing the eyelid's protective function, ectropion can cause epiphora, lagophthalmos, keratinization, chronic irritation, pain, and ulceration. There are 5 types of ectropion, each with a different cause: congenital, paralytic, involutional, cicatricial, and mechanical. The most common presentation in dermatology is involutional eversion with a mechanical or tractional element. Several options exist for the surgical repair of ectropion and choice of technique will depend on the main pathogenic component. We review the basic anatomy of the eyelid and describe examination techniques for assessing risk and preventing ectropion and for identifying the main pathogenic component in order to select the most suitable repair technique.