The yellow tricholoma (Tricholoma flavovirens or Tricholoma equestre) is a wild mushroom species that was previously considered edible and tasty. Recently, it caused several cases of delayed rhabdomyolysis in humans and elevated serum creatine kinase (CK) activities in laboratory mice (Mus musculus) in a dose-response study. The present study continued to examine the effects of prolonged T. flavovirens consumption at 12 g freshly frozen mushroom kg(-1)d(-1) on the plasma clinical chemistry and organ histology of mice. The plasma CK and CK-MB activities and the plasma bilirubin concentrations were higher in the exposed mice than in the controls. In addition, pericardial lymphocyte infiltrates were present in the mice that had consumed the mushroom. The results indicate myo-, cardio- and hepatotoxic effects of T. flavovirens.