OBJECTIVES: The aim of this study is to evaluate the impact on the hospital budget of the introduction of a biological therapy, rituximab, in the treatment of rheumatoid arthritis after failure of a conventional therapy, methotrexate METHODS: This is a budget impact analysis including patients of El Ayachi Hospital with severe rheumatoid arthritis who received rituximab during the period from 15 July 2014 to 15 July 2015 and benefiting from the Medical Assistance Plan. We compared two strategies: Strategy A, methotrexate alone and strategy B, rituximab + methotrexate. To compare the total annual cost of both treatment strategies, data on the annual cost of treatment, hospitalizations and consultations, biological and radiological assessments and other imaging tests were collected. RESULTS: Among patients who received rituximab during the period of 12 months, 68% of them benefited from the Medical Assistance Plan. This corresponds to 47 patients. The annual treatment costs per patient were $140.12 with strategy A against $6,350.72 with strategy B. The annual costs of hospitalizations and consultations, pre-treatment assessments, monitoring assessments and additional assessments were respectively $237.46, $89.05, $184.74 and $240.08 with the strategy A. However, these costs were respectively $185.14, $281.84, $92.37 and $290.39 with the strategy B. Thus, the annual cost per patient was $891.45 with strategy A against $7,200.46 with strategy B. This corresponds to respective annual global costs of $41,898.29 and $338,421.61 for the hospital. This leads to a ratio of 1/8. CONCLUSIONS: The introduction of rituximab after failure of methotrexate in the treatment of rheumatoid arthritis has a significant impact on the budget of El Ayachi Hospital. The management of patients with severe rheumatoid arthritis and benefiting from theMedical Assistance Plan requires a special management of the health facility budget.