The purpose of this paper is to argue for the necessity of a rigorous sexual science. The consequences of the absence of a sexual science and data on human sexual behavior are noted. Similarly, the obstacles which prevent a rigorous sexual science are also discussed. Finally, suggestions for the future of sexual science are introduced. Sexual science is defined, simple goals are described, measurement issues are examined, and theoretical objectives are suggested. The paper concludes with the following statement:“Future generations will find it incomprehensible—and perhaps unconscionably negligent—that so little effort was marshalled to obtain data on, and establish a science of, human sexual behavior.”