Telesensing, or probing of the environment by the release of chemical messengers, plays a central role in the sexual programs of microbial organisms. Sex pheromones secreted by mating cells are sensed by potential partner cells and mediate cell-to-cell contact and the subsequent exchange of genetic material. Although the mechanisms used by bacterial and fungal species to promote genetic exchange are distinct, recent studies have uncovered surprising parallels between pheromone signaling in these species. In addition, it is now apparent that pheromone signaling not only controls sexual reproduction and genetic exchange but can also activate expression of potential virulence factors in diverse opportunistic pathogens.