Cluster headache has long been considered a predominantly male disorder, with much of our knowledge based on studies of men. However, it has become increasingly more recognized in women. Although there are many similarities between men and women in the expression of the disorder, studies over the years have revealed gender differences. This article reviews epidemiologic, clinical, hormonal, and familial differences between male and female cluster patients, examines how they may affect treatment, and suggests studies that may give us a better understanding of the disorder.