Introduction: Early ICH expansion is associated with a higher rate of poor outcomes and death in aSAH patients, especially in limited-resource settings. This study aimed to investigate the impact of ICH expansion on the outcomes and the factors related to an ICH expansion in aSAH patients in an LMIC. Hypothesis: Understanding factors related to ICH after an aneurysmal rupture in different countries, particularly in limited-resource regions, is crucial for reducing poor outcomes and mortality. Methods: We performed a multicenter prospective cohort study of patients (≥18 years) presenting with aSAH at three central hospitals in Hanoi, Vietnam, from August 2019 to June 2021. We collected data on the demographics, baseline characteristics, management, and outcomes and compared these data between patients who had an ICH expansion (defined as ICH detected on an admission CT scan) and patients who did not. We assessed factors associated with ICH expansion on admission using logistic regression. Results: Of 415 patients, 198 (47.7%) were men, and the median age was 57.0 years (IQR: 48.0-67.0). ICH expansion accounted for 20.5% (85/415) of aSAH patients. There was a significant difference in the 90-day poor outcomes (43.5%; 37/85 and 29.1%; 96/330; p=0.011) and 90-day mortality (36.5%; 31/85 and 20.0%; 66/330; p=0.001) between patients who had ICH and patients who did not have ICH expansion. The multivariate analysis showed that systolic BP of 140 mmHg or more (OR: 2.674; 95% CI: 1.372-5.214), WFNS grades II (OR: 3.683; 95% CI: 1.250-10.858) to V (OR: 6.912; 95% CI: 2.553-18.709), and a ruptured MCA aneurysm (OR: 3.717; 95% CI: 1.848-7.477) were independent predictors of ICH expansion. Conclusions: In our study, ICH accounted for a substantial proportion of aSAH patients and contributed significantly to a high rate of poor outcomes and death. On admission, a higher systolic BP, a worse neurological status, and a ruptured MCA aneurysm were independent predictors of ICH expansion. This study indicates independent predictors of an early ICH expansion, such as a higher admission systolic BP and a worse initial neurological status, after aneurysmal ruptures that require only a clinical examination and, therefore, may be particularly valuable in resource-limited settings.