The Hospital Based Cancer Registry in Registry in Cipto Mangunkusumo National Center General Hospital (RSCM), the teaching hospital of the Faculty of Medicine University of Indonesia, was set up in 1997. Its aims were to provide information on the magnitude of cartcer problems, and data for focussing cancer control programs, to facilitate the follow up and to help plan hospital facilities. This paper presents a summary of the cancer registry data collected during the period of 1997-1998. Data from al newly diagnosed cancer patients was recorded in Cancer Registration Forms by the oncology doctors. The collected items of information were patient’s identification, demographic and cultural items, the tumor and its investigations, and the treatment. There were 2144 (0.48%) cancer patients among 444.178 new patients treated in RSCM hospital. The female to male patients ratio was 1.7:1. The age peaked in females within 35-44 years, and in males within 45-54 years. In general, the mean age at diagnosis of various cancer was younger compared to other centers. In females, the most common cancers were cervical, breast, and nasophayngeal. and in males, they were nasopharyngeal, bone marrow, and liver cancers. In children, the most common cancers were acute lymphocytic leukemia, acute non-lymphocytic leukemia, acute non-lymphocytic leukemia, retinoblastoma, and nephroblastoma. Female patients had lower educational level than males. Females with cervical, skin, bone marrow, lymph nodes cancer and males with bone marrow, lymph nodes and eye malignancy had lower educational level. There were 85% patients diagnosed by microscopic examination. The number of early stage cancer was lower corned to late stage cases (47% vs 53%). In 1998. the most frequent initial treatment was radiotherapy, followed by surgery and chemotherapy, and only 45% patients received treatments within 3 months after diagnosis. © 2000, Faculty of Medicine, Universitas Indonesia. All rights reserved.