OBJECTIVES: Due to advances in medical technology, cancer care costs are growing rapidly and expenditures with oncology treatment represents a significant burden for managed care organizations. Therefore, the study aims to evaluate the profile of oncology patients and treatment costs from UNIMED São José do Rio Preto (USJRP), a medical cooperative responsible for approximately 118,000 lives in São Paulo, Brazil. METHODS: A review of USJRP administrative claims database was conducted for patients who were under any cancer treatment between January 2011 to December 2011. Data regarding gender, age and treatment expenditures were assessed for the entire period. Only costs associated with treatment were taken into account (i.e. drugs, devices/materials and room taxes). Type of cancer was identified according to ICD-9 codes and grouped into major cancer types. Costs were reported in Brazilian Reais (1.00US$~2.00BRL Jun/2012). RESULTS: A total of 324 oncology patients were identified (44.0% male and 56.0% female) with overall expenditures in the study period of BRL 4.57 million. Average age was 59.2 years (55.4 for female and 64.4 for male). Drugs accounted for 93.4% of all treatment expenditures, followed by room taxes with 4.2%. Average treatment cost per patient was BRL 14,105, being lymphoma the most expensive type of cancer (BRL 15,544 per patient). In terms of overall costs, breast cancer represented 43.8% of all treatment costs (BRL 1.98 million), followed by colorectal cancer (24.0%; BRL 1.10 million) and lung cancer (12.0%; BRL 0.55 million). CONCLUSIONS: More than 300 patients were treated for cancer in 2011 which accounted for approximately BRL 4.57million, being drugs responsible for more than 90% of all treatment expenditures. In 2011, healthcare costs reported for USJRP was BRL 217,849,541 (average of BRL 1,850 per life), demonstrating that costs associated with oncology treatment are high and suggesting the importance of economic evaluation of cancer drugs for the decision making process.