INTRODUCTION: Early neurological deterioration (END) in ischemic stroke (IS) patients is a common complication that significantly impacts functional and vital prognoses. We aimed to determine the prevalence, predictors, and 90-day outcomes of END in Tunisian stroke patients. MATERIALS AND METHODS: This was a retrospective cohort study of consecutive stroke cases admitted at the Neurology Department of the University Hospital in Monastir over 5 years, from 2018 to 2022. We included patients with an increment of two or more points on the NIHSS score within the first 7 days following IS. Univariate analysis and binary logistic regression were performed to identify independent factors associated with END. RESULTS: We included 489 patients with a mean age of 64 years (24 to 90) and a male predominance (sex ratio M/F = 1.86). The prevalence of END was 12.06% (59/489 patients). An elevated initial NIHSS score (OR = 1.13
95% CI = 1.05-1.21), anterior choroidal artery stroke (OR = 5.39
95% CI = 1.99-14.55), and large artery atherosclerosis (OR = 2.85
95% CI = 1.17-6.9), were found to be independent factors associated with END. The causes of END included IS recurrence (12%), hemorrhagic transformation (10%), brain edema (10%), and stroke progression (68%). At 90 days, 80.8% ( CONCLUSION: Patients with elevated NIHSS scores, AChA strokes, or LAA, should be prioritized for close observation during the acute phase. Enhancing our understanding of the predictive factors of END following IS could help target patients at very high risk of END and facilitate the development of more effective and rigorous strategies for prevention and treatment.