Toxic shock syndrome (TSS) is an acute febrile disease with multiple organ involvement caused by massive and rapid release of cytokines induced by staphylococcal exotoxins. However, the precise cytokine profile is still undefined in clinical cases. We measured serum cytokine concentrations in a patient who developed TSS after a caesarean section. Measurements were taken on admission and several times during the course of the disease. Methicillin-resistant Staphylococcus aureus producing TSS toxin-1 and staphylococcal enterotoxin C was detected in the lochia and venous blood. Serum interleukin (IL)-6 level was markedly increased on admission, and IL-10, tumour necrosis factor-alpha, and interferon-gamma levels were also raised. These cytokine levels rapidly returned to normal levels. In contrast, IL-1beta and IL-2 were below the analytical sensitivity threshold throughout the course. Our data and other previous case reports indicate that a marked increase in IL-6 concentration could be a clinical marker of TSS onset.