OBJECTIVES: To estimate the incremental budget impact of the reimbursement of long-acting insulin analogues (LAIA) for type 1 diabetes patients (T1DM) in Brazil.  METHODS: A budget impact analysis (BIA) of LAIA in the Brazilian public health system compared to NPH human insulin was performed. The analysis’ time horizon was 5 years. The target population used the methodology of epidemiological demand, considering estimates of the International Diabetes Federation: 11.6 million diabetics of 20-79 years old x 5% T1DM plus 31100 children and 10845 adolescents. It considered the incidence of 10.4/100,000 persons per year and mortality 23.15/1000 adults per year. The overall mean insulin dose was obtained from trials. For the human insulin, we considered the values of last purchase of the Ministry of Health. For both insulins, we got the average maximum sale price for government from CMED list. Then the bargaining power was calculated dividing the NPH's maximum sale price by the Ministry's purchase price, and we applied 50% of the bargaining power to the LAIA's price. Market share was 50%, 60%, 70%, 80% and 80%.  RESULTS: The incremental budget impact of LAIA would be $93 million in the 1st year, considering 50% of target population, and reaching approximately $432 million for 80% of patients. In 5 years, the calculated budget impact was $617 million. The sensitivity analysis indicates the prevalence and analogues prices as villains. CONCLUSIONS: LAIA are available in Brazil since 2002, although to this day the public health system does not make it available to citizens. We can suggest that the reason for non-coverage is the considerable budget impact, nevertheless our analysis, more complex and with rational methodology, have shown less impact than the analysis used in the Ministry's decision, which BIA was U$ 816 million for the coverage of LAIA.