OBJECTIVES::  The aim of this study is to describe costs related to conventional and biological therapies in patients diagnosed with rheumatoid arthritis in Colombia. METHODS:: This is a cost description analysis focusing on quantifying direct medical cost by bottom-up approach. We calculated the use of resources of patients treated under a patient centered care model (PCC) in a specialized rheumatology center in Bogotá, Colombia. We estimated costs of conventional and biological therapies in patients with rheumatoid arthritis. Direct medical costs were analyzed from the third payer perspective. Costs were calculated using billing and price information and the official national prices health services databases such as the official Colombian Tariff Manual (SOAT in Spanish), which standardize the maximum price of medical, surgical and hospital prices. Drugs costs were estimated using a national official drugs database (SISMED in Spanish), which contains median estimates and range prices for drugs in the country. Costs were estimated in Colombian pesos and American dollars (1 US$ = COP$3,000.71) of 2016. RESULTS:: The direct medical median cost of treating patients with rheumatoid arthritis using the conventional therapy was COP$3,662.000 (US$1,220.4). Of these, 1.6% were due to specialized consultation, 3% to laboratory and images tests, 3.3% to other costs and 92.1% due to DMARDs drugs. The direct medical cost of biological therapy was COP$28,591,014 (US$9,528). The main driver of the direct cost were the biological drugs (92.9%). Also, 5.9% of the cost was due to conventional therapy, and 1,2% due to outpatient visits, labs and images tests. Comparing these therapies, we can highlight that treating patients with biological treatment is 7.8 times costlier that the ones treated with conventional treatment. CONCLUSIONS:: Rheumatoid arthritis is a leading problem of public health worldwide. Conventional and biological drugs were the largest expenditure in the treatment of rheumatoid arthritis.