Recognition that genetic conflict affects evolutionary change at all levels of biological organization has shaped Evolutionary Biology in the last 40 years. Conflicts over sex arise whenever the optimal reproductive strategies of females and males differ (i.e., whenever there is promiscuity). Much of the recent interest in sexual conflict has focused upon mating conflict, manifest as coercion and resistance to coercion. In this kind of battle, proliferation occurs because characters that alter the frequency or outcome of sexual interactions to the benefit of one sex compromise the other sex by moving it further from its optimum. An ‘arms race’ may ensue, as the harmed sex evolves counter-measures. This kind of conflict has been dubbed ‘interlocus sexual conflict’ to emphasize the idea that adaptation involves different loci in the two sexes. Even more fundamental but less emphasized is the fact that selection for different fitness optima in the two sexes can create intralocus sexual conflict. My lab’s work suggests that intralocus sexual conflict is an important contributor to the maintenance of genetic variation in populations and a key contributor to the incidence of genetic disease. I will discuss my own findings and those from a string of studies identifying this form of genetic conflict.