Background and aims Early neurological deterioration (END) in acute ischemic stroke (AIS), patients is defined as clinical worsening or recurrence during first 72 h after onset of AIS. We have conducted this study to determine the association between END and functional outcome at 3 months of onset of AIS along with associated risk factors of END in AIS cases. Methodology This study was conducted after approval of Institute Ethics Committee. Two hundred three consecutive patients were admitted from September 2020 to January 2022 at a tertiary care hospital. One hundred ninety patients were included in the study; patients were divided into two groups: (1) early neurological deterioration (END) and (2) non-early neurological deterioration (non-END). Patients were followed-up either telephonically or in person at approximately 3 months using modified Rankin Scale 0–6. All the clinically significant prognostic markers and p  < 0.10 variables were considered significant in univariate analysis; P  < 0.05 were considered statistically significant for the multivariate analysis. Results Out of 190 cases included in the cohort 34/190 (17.8%) cases showed END with mean age (56.56 (± 16.6)) and males (20/34 (58.8%)). END was independently associated with high blood glucose at admission (OR = 1.015; P  = 0.002; 95%CI = 1.005–1.024) and low serum albumin (OR = 0.208; P  = 0.002; 95%CI = 0.077–0.562). Patients with END showed poor functional outcome (mRS > 2) at end of 3 months (32 (94.1%); P  < 0.001) and death was also statistically significant (22 (64.7%); P  < 0.001) as compared to AIS cases having non-END. Conclusion Our study showed END may be associated with poor functional outcome in AIS patients. Higher blood glucose at admission and low serum albumin may be statistically significant causing END. Future prospective cohort with larger sample size may confirm the findings.