Background-Among several factors reported to predict outcome of stroke, dehydrated appears to have poor functional outcomes. Unfortunately clinical methods to gauge hydration are not accurate, especially in geriatric patients hence, biochemical parameters like BUN/creatinine ratio(BUN/Cr) would be valuable marker for dehydration in stroke patients. Aim-To determine frequency and risk factors of dehydration in acute stroke patients, and impact on outcome at 30 days. Methods-An observational, prospective study conducted over 6-months. All adult patients presenting with acute stroke in first 24 hrs after symptom onset were included. Patients with previous history of stroke, TIA or congestive cardiac failure, renal failure and de-compensated cirrhosis of liver were excluded. Demographic, clinical and laboratory parameters were recorded. The primary outcome was determined at 30 days by modified Rankin Scale. Results-116 patients were enrolled in study with 103(88.7%) patients having ischemic stroke while 13(11.2%) had hemorrhagic stroke. Analyzing baseline factors, older age, higher stroke severity(NIHSS >16), low GCS(<8), and BUN/Cr>15 were significantly(p<0.001) associated with dependency(mRS>2) or mortality at day 30. On multivariate analysis, dehyration (BUN/Cr>15) was found in 53.4% and was one of the independent predictors of poor short-term outcome. In this study, 53.4%patients had BUN/Cr ratio >15(Group I) while 46.6% with BUN/Cr ratio≤15(Group II). Mean age (64.4±12.15 years) was significantly higher in Group I compared to Group II(57.9±8.7 years). On univariate analysis, diabetes(48.4% vs 20.4%) and coronary artery disease(41.9% vs 18.5%) were statistically significant associated with dehydration at time of acute stroke. Higher NIHSS score and low GCS were also statistically significant in Group I. From multivariate analysis older age group, low GCS and CAD were independent predictors for hydration status at time of acute stroke. Conclusion- Our findings support that BUN/Cr ratio(rapid, cheap, and easily available parameter) should be included in routine assessment of all stroke patients and is one of the independent predictors of poor outcome.