Two strains of Staphylococcus epidermidis isolated from patients with toxic shock symptoms have been reported to carry genes related to S. aureus enterotoxins B and C by dot-blot hybridisation, although the corresponding superantigenic toxins were not detected immunologically. We here show that these strains produce no superantigens capable of stimulating proliferation of human mononuclear leukocytes or rabbit splenocytes, and that no DNA homologous to the seb or sec genes can be detected by PCR. However, stimulation of human monocytes by whole killed bacteria induced dose-dependent production of the cytokines TNF alpha, IL-1 beta and IL-6, which may be responsible for the clinical symptoms in these patients.