It is rate for one human being to be afflicted with more than one cancer. However with further advances in therapeutic regimens histopathologic observation diagnostic modalities and incre-ased curiosity there are increasing number of case reports of multiple primary cancer. The present study evaluates 25 histologically confirmed cases of multiple primary cancer from 1974 to 1988 at Kosin Medical Center the most frequent site of the first primary cancer in male was stomach and in fmale uterine cervix The first primary cancer in female occurred in endocrine-related organs (breast uterus and thyroid) in 63.6 percent. The most frequent site of the first primary cancer in male was stomach and in fmale uterine cervix. The first primary cancer in female occurred in endocrine-related organs(breast, uterus and thyroid) in 63.6 percent. Synchronous cancers are diagnosed simultaneously or within an interval of about six months and synchronous cancers were 16 out of 25 cases. Metachronous cancers are diagnosed at interval of more than six months. There were 9 metachronous cancers and average interval between the first and second primary cancer was 0.11 percent. The average age was 51.9 years at the time of the first primary cancer (53.1 years in male and 50.3 years in female). CT scan was most helpful in early detection of multiple primary cancers facilitating biopsy and surgery. Multiple primary cancers are beyound the medical curiosity. Early diagnosis of the disease and careful follow-up study bascd on an awareness of the possibility of second cancers will substantially increase the survival of these patients.