High blood pressure is a major individual and public-health issue because of its wide prevalence and associated complications. More women than men have hypertension, but until recently, women have been relatively underrepresented in clinical trials. Gender differences in the physiology, genetics, and treatment benefit of hypertension have been noted in several studies that have included women. These findings have raised concerns about the generalizability of the results of previous investigations to women. The currently available information regarding gender differences and similarities and the results of hypertension treatment trials in women are reviewed herein. These studies suggest that, although gender differences exist, women benefit significantly when they receive therapy to normalize blood pressure.