We report a unique case of a patient with synchronous renal cell carci
noma, hepatocellular carcinoma and squamous cell carcinoma of the oral
floor. All three tumors were resected during a single operation. The
patient was a 75-year-old man with masses in the liver and right kidne
y discovered by ultrasound examination during a routine checkup. Furth
er examination also revealed a squamous cell carcinoma of the oral flo
or. The patient underwent a simultaneous radical nephrectomy, enucleat
ion of the liver tumor and resection of the tumor of the oral floor. T
he diagnoses were histopathologically confirmed. The number of patient
s with multiple cancers has recently been increasing. The possibility
of a second or third malignant lesion should be considered, not only i
n patients with a known malignancy but also in those without malignanc
y. The importance of screening procedures in the early detection of ma
lignancy before the appearance of clinical symptoms should be emphasiz
ed.