Previous studies have shown an analgesic effect of ginger in the acute treatment of migraine, and there is anecdotal evidence of its efficacy in migraine prophylaxis. This study aimed to evaluate the potential of ginger to prevent migraine attacks. This double-blind, placebo-controlled randomized clinical trial took place at the Headache Clinic, Universidade Federal de Minas Gerais (Belo Horizonte, Minas Gerais, Brazil), involving 107 patients. Only subjects diagnosed with episodic migraine, aged between 18 and 60 years old, and who were not taking any prophylactic medication, were enrolled in the study. After one month of observation, subjects selected for the study were randomized 1:1 into placebo and treatment groups. Patients received capsules three times per day of 200 mg of dry extract of ginger (5% active ingredient) or placebo (cellulose) for three months. Visits were performed monthly and the patients were asked to fill in a migraine diary. The adherence to treatment was evaluated by counting capsules. The percentage of patients who responded to treatment (i.e. a reduction of 50% in the number of migraine attacks at the end of treatment) did not differ between the groups. There was a decrease in the number of days with severe pain, analgesic use for acute migraine and duration of migraine attacks in both groups, without significant difference between ginger and placebo groups. Ginger provides no greater benefit in the prophylactic treatment of migraine when compared to placebo. This trial is registered at ClinicalTrials.gov (NCT02570633).