BACKGROUND: During the natural history, the incidence HTLV-1 related diseases were 0.5% until 10% after decades of infection. Despite relative low lethality, previous study observed that HTLV-1 infection is associated with significantly increased mortality. For example, the incidence of ATLL and HAM/TSP, co-infections with HIV and HCV, parasitic co-infection with Strongyloides stercoralis may increase morbidity and mortality. OBJECTIVE: Determine the mortality rate and its major variables as possible risk factors, analyzing the HTLV Clinic at Emilio Ribas Institute, a continuous open cohort of HTLV patients since 1997. METHODS: This cohort open cohort possesses new patients added at a rate of approximately 50 patients/year. There were 1100 HTLV-infected subjects identified by September 30th 2018. All clinical data including clinical and laboratory data, which have been updated on a regular basis over the last 22 years, were entered into a specific REDCap database. The Ethical Board of the IIER approved the protocol. RESULTS: Along 22 years of clinical care in the HTLV-out clinic, 727 HTLV-1-infected subjects and 248 HAM/TSP cases. Four-hundred sixty-eight patients of whom remaining under active follow up. The mean follow-up time of the cohort was 12 years. Twenty-seven patients died (median age of 51,5 years old). From this total, 13 was asymptomatic carriers and 14 HAM/TSP subjects, 12 of asymptomatic and seven HAM/TSP possess co-infected with HIV or/and HCV. Other seven presented HAM/TSP without co-infection, and all was female, and sepsis was the majority cases the majority of cases of sepsis were related to infection of the urinary tract (p=0.058) and to ulcers of decubitus (p=0.021), and it was associated with risk factors for mortality. CONCLUSIONS: Overall, the mortality rate for HAM-TSP patients was six percent. The mean life expectancy in Brazil is about 78 years in 2018, twenty-two years higher than HAM/TSP patients without any other coinfection. This study highlights the possibility of higher death risk among HTLV-1-infected patients and HAM/TSP subjects in Brazil, and identified some risk factors for this outcome. Also, these patients may possess higher risk for morbidity, usually urinary tract infections and decubitus scars, which could increase risk for death.