Pyomyositis is a primary bacterial infection of skeletal muscle. This infec
tion tends to occur in the large muscles of the lower extremity. Pyomyositi
s of the proximal muscles of the thigh can simulate acute abdominal disease
. Early diagnosis improves the outcome. Delayed diagnosis may lead to septi
cemia and schock. We report the CT and MRI findings in a patient with pyomy
ositis of the proximal muscles of the thigh.