Because of the frequency with which Staphylococcus aureus and Streptococcus pyogenes infections occur, physicians are quite familiar with the diversity of their clinical presentations. In the 1970s, however, shock associated with multiorgan failure was described in menstruating female patients as well as in male patients following a variety of surgical procedures, such as rhinoplasty. This previously undescribed presentation of S. aureus infection, termed staphylococcal toxic shock syndrome, was associated with unique strains of S. aureus. In the mid-1980s, the emergence of streptococcal toxic shock syndrome was heralded by several case reports describing patients with group A streptococcal infections associated with shock and organ failure. This article compares the differences in the epidemiologic, clinical, and pathophysiologic features of the toxic shock syndromes.