Background: Hyponatremia is the most common electrolyte abnormality seen in intracerebral hemorrhage (ICH) and is associated with a nearly doubled mortality rate and more severe presentations. However, the current literature has not addressed what factors might predispose ICH patients to presenting with hyponatremia or developing it during their hospital stay. The aim of this study was to evaluate the characteristics, comorbidities, and inpatient outcomes prevalent amongst ICH patients with hyponatremia. Methods: A retrospective study was performed for 814 adult patients admitted from January 2011-December 2022 with primary ICH at Stony Brook University Hospital. We recorded sodium and serum chemistry levels throughout admission, medical history, radiographic hematoma volumes, and Modified Rankin Scale (MRS) and Glasgow Coma Scale (GCS) up to 1-year follow-up. Results: Hyponatremia on admission was seen in 79 (9.8%) patients. Another 311 patients (38.3%) developed hyponatremia during their hospital stay. Pre-existing hyponatremia was correlated with a history of diabetes while hyponatremia during stay was correlated with diabetes, liver disease, heavy drinking, and prior valve replacement. Complications such as pneumonia, UTI, or a bloodstream infection were more prevalent in patients with hyponatremia. They also had a longer hospital stay and higher inpatient mortality (χ2(1)=5.176, p=0.023). Patients with hyponatremia had significantly lower GCS values on discharge. A multivariate regression analysis of age, admission MRS, diabetes, liver disease, ICH score, volume, and minimum Na was statistically significant ( R 2=0.255, F(7,704)=34.46, p<0.001). Minimum Na reliably predicted death in this model (β=0.007, p=0.023). Conclusions: Several factors can predispose ICH patients to hyponatremia on presentation or be associated with developing hyponatremia during their hospital stay. This study showed that developing hyponatremia during the hospital stay was associated with worse outcomes at discharge. In addition, hyponatremia can significantly predict inpatient mortality when controlling for ICH severity and common aggravating factors.