In 183 clinical isolates of Staphylococcus aureus, toxic shock syndrome toxin was detected in 13.7%, enterotoxin A in 20.2%, enterotoxin B in 7.7%, enterotoxin C in 5.5% and enterotoxin D in 3.3%. Seventy-three (39.9%) of the strains were found to produce one or more toxins. Multiple secretion of toxins was rare (< 1% of all strains) except for the combinations enterotoxin A with toxic shock syndrome toxin and enterotoxin A with enterotoxin D. These combinations were observed at significantly higher frequencies (4.9% and 2.2%, respectively) than would have been expected from values calculated from respective individual frequencies (0.88% and 0.06%) (p < 0.0001). In comparison with Staphylococcus aureus strains isolated from miscellaneous material, Staphylococcus aureus blood culture isolates produced enterotoxin D in significantly larger amounts and at higher frequencies (p = 0.01 in both cases). These toxins might play an important pathogenic role in Staphylococcus aureus infections.