This systematic review of the literature addresses the medical management of spasmodic dysphonia (SD) and some related conditions. It was carried as part of the development of practice guidelines for the Academy of Neurologic Communication Disorders and Sciences (ANCDS). A search of electronic databases (PsychINFO, MEDLINE, and CINAHL) and hand searches of relevant edited books yielded 103 intervention studies in the categories of recurrent laryngeal nerve (RLN) section (20 references), the use of botulinum toxin (Botox) injections for the management of SD (58 references), and miscellaneous interventions (25 references). A review of this literature suggests that RLN section as a treatment for adductor SD results in a substantial degree of improvement for a substantial percentage of patients, but that recurrence of SD signs and symptoms is common. Botox injection also results in a substantial degree of improvement for a substantial percentage of patients. Benefits generally last for 3 to 4 months, but reinjection is required to maintain the effect. The side effects of a weak or breathy voice and mild dysphagia last for several weeks in many patients. The effectiveness of Botox injection for abductor SD is less pronounced and occurs in a smaller percentage of patients than adductor SD. Other surgical techniques may be of benefit when Botox injection is not successful or, as an alternative to Botox injection, but evidence for their effectiveness currently is limited. Directions for future research are provided.