Ethical Approval: This article adheres to ethical guidelines and was approved by the Ethics. Review Board of the Evandro Chagas National Institute of Infectious Diseases—Oswaldo Cruz Foundation (Rio de Janeiro). The data were de-identified for analysis.Background: Aneurysmal subarachnoid hemorrhage (SAH) is associated with high mortality and long-term functional impairment. Data on clinical management and functional outcomes from developing countries are scarce. We aimed to define patient profiles and clinical practices and evaluate long-term outcomes after SAH in a middle-income country. Methods: This was a prospective study including consecutive adult patients admitted with SAH to two reference centers in Brazil from January 2016 to February 2020. The primary outcome was functional status at 6 months using the modified Rankin Scale. Mixed multivariable analysis was performed to determine the relationship between clinical variables and functional outcomes. Results: From 471patients analyzed, the median time from symptom onset to arrival at a study center was 4 days (interquartile range 0-9). Median age was 55 years (interquartile range 46-62) and 353 (75%) patients were women. A total of 426 patients (90%) were transferred from nonspecialized general hospitals, initial computed tomography revealed thick hemorrhage in 73% of patients (modified Fisher score of 3 or 4), and 136 (29%) had poor clinical grade (World Federation of Neurological Surgeons score of 4 or 5). A total of 312 (66%) patients underwent surgical clipping, and 119 (25%) underwent endovascular coiling. Only 34 patients (7%) underwent withdrawal or withholding of life-sustaining therapy during their hospital stay, and in-hospital mortality was 24%. A total of 187 (40%) patients had an unfavorable long-term functional outcome (modified Rankin Scale score of 4 to 6). Factors associated with unfavorable outcome were age (adjusted odds ratio [OR] 1.05, 95% confidence interval [CI] 1.03-1.08), hypertension (adjusted OR 1.81, 95% CI 1.04-3.16), poor clinical grade (adjusted OR 4.92, 95% CI 2.85-8.48), external ventricular drain (adjusted OR 3.8, 95% CI 2.31-6.24), postoperative deterioration (adjusted OR 2.33, 95% CI 1.32-4.13), cerebral infarction (adjusted OR 3.16, 95% CI 1.81-5.52), rebleeding (adjusted OR 2.95, 95% CI 1.13-7.69), and sepsis (adjusted OR 2.68, 95% CI 1.42-5.05). Conclusions: Our study demonstrated that SAH management in a middle-income country diverges significantly from published cohorts and current guidelines, despite comparable clinical profiles on presentation and admission to high-volume referral centers. Earlier aneurysm occlusion and increased use of endovascular therapy could potentially reduce modifiable in-hospital complications and improve functional outcomes in Brazil.2030-12-31