Extraocular muscle biopsy is a technique used for the histological diagnosis of several orbital diseases; it could bring valuable assistance to the diagnostic process. The purpose of this article is to review the indications, surgical technique, and complications of this biopsy.Extraocular muscle biopsy is frequently used in tumoral pathology, however, in inflammatory diseases, it is only used when facing a poor reaction to the treatment or in case of chronicity. The surgical procedure must be precise and least traumatic, in order to avoid intra-and post-operative complications, but also to preserve the integrity and function of the muscle. This procedure remains non-standardized and not devoid of complications, hence the need for a careful evaluation of the benefit/risk ratio before considering it.