Introduction: Chronic lymphocytic leukemia(CLL) has a highly variable clinical course. It is important to understand the aspects that affect the outcomes of CLL in a real-world setting. Data from the Brazilian Registry of CLL was analyzed to compare clinical and treatment-related characteristics in patients with CLL treated in public or in private institutions in Brazil. Objective: To describe the outcomes of a series of CLL patients followed in public or in private hospitals in Brazil. Methods: Inclusion criteria for enrollment followed the IWCLL guidelines. We included all patients with minimum available data for analysis of patient and disease characteristics and survival. Results/Discussion: From January 2004 to July 2020, 3031 patients from 37 centers met eligibility criteria for this analysis: 2427 (80%) were followed at public hospitals and 604(20%) at private hospitals. The majority were male (57%), with median age of 66 years(range:23-106). Binet stage was A in 1677 (58%) patients, B in 652 (23%), C in 540 (19%). FISH for del(17p) was performed in only 483 patients (16%), while FISH for the most common aberrations [del(13q),+12,del(11q),del(17p)] was performed in only 447 patients(15%). IGVH mutational status was performed in 213 patients (7%), and karyotype in 154 patients (5%). Comparing public and private hospitals, we observed that patients in public hospital are slightly older (median age 66 vs 63 years for private hospitals, p < 0.0001), had more advanced diseases at diagnosis (frequency of Binet B or C was 44% in public vs 33% in private hospital, p < 0.0001), and there were more patients with elevated creatinine levels(18% vs 10%, p = 0.03). All prognostic markers were more available in private than in public hospitals: FISH for del17p(42% of cases vs 10%, respectively, p < 0.0001), IGVH mutational status(13% vs 6%, respectively, p < 0.0001) and karyotype (16% vs 3%, respectively, p < 0.0001). The frequency of del(17p) was similar between public and private hospitals (10% vs 11%, p = NS), while the frequency of unmutated IGHV status was more common in private hospitals, although not statistically different (60% vs 48%, p = 0.09). Analyzing 2175 diagnosed after 2008,1019 patients (47%) were treated after a median time of 4 months (range:0-129) after diagnosis. First line treatment was predominantly based chlorambucil (45%) or fludarabine (40%). Anti-CD20 monoclonal antibody was used in only 39% of cases: (rituximab in 35%, obinutuzumab in 4%). Novel agents were used in first line in only 2% of patients. Most patients (86%) with del(17p) detected by FISH were treated with chemoimmunotherapy. When comparing treatments between public or private hospitals we observed striking differences: in public hospitals there were significantly less patients receiving fludarabine-base regimens(34% vs 53%, p < 0.0001), and anti-CD20 monoclonal antibodies (27% vs 78%, p < 0.0001). Overall survival at 6 years was significantly worse in public than in private hospitals (71% vs 91%, respectively, p < 0.0001). Survival in patients from public hospitals remained significantly worse than in private hospitals (hazard ratio 3.9, 95% confidence interval 1.8–8.5), after correcting for age, Binet staging and renal function. Conclusion: Our data indicate that there are striking differences between patients treated in public or private hospitals in Brazil. The lack of accessibility to basic laboratory tests for prognostic factors and adequate therapies probably explains the worse outcome of patients treated in public institutions. Prognostic testing rates were poor in both contexts and most high-risk patients received chemoimmunotherapy first-line.