From the pandemics of the 19th century to the recent disaster in Goma, Zaire, cholera has left an indelible mark on human and medical history. Cholera pandemics in the 19th and 20th centuries drove the development of epidemiology as a serious science. Cholera has continued to press advances in the concepts of disease ecology, basic membrane biology, and transmembrane signaling and in the application of scientific information to treatment design. Furthermore, the lessons learned from the study of pandemic cholera are likely to provide insights into the best means of stopping other pandemics. In spite of tremendous scientific and clinical progress, however, the seventh pandemic has lasted 33 years, and the eighth pandemic appears to have started.