Admission stroke severity, commonly quantified using the National Institutes of Health Stroke Scale (NIHSS), strongly influences early complications and long-term outcomes. However, evidence from routine clinical practice regarding whether a cumulative burden of vascular risk factors relates to initial severity remains limited. To address this, a cross-sectional analysis of consecutive stroke admissions recorded in a tertiary-care stroke registry between January 2020 and December 2024 was conducted. Exposure was defined as the cumulative count of eight prespecified vascular risk factors—hypertension, diabetes mellitus, dyslipidemia, current smoking, coronary artery disease, heart failure, atrial fibrillation, and prior transient ischemic attack—while the outcome was admission NIHSS score. Among the 1988 screened records, 1676 unique adult index admissions were analyzed. The cumulative risk-factor count demonstrated a weak but statistically significant positive correlation with overall admission NIHSS scores and within both ischemic and hemorrhagic subtypes. In adjusted multivariable analyses, hypertension, diabetes mellitus, heart failure, and smoking were independently associated with higher NIHSS scores, whereas dyslipidemia and coronary artery disease showed inverse associations. These findings indicate that a greater cumulative vascular risk-factor burden is associated with worse admission stroke severity, reflecting a modest dose–response relationship that complements lesion-level determinants in early stroke assessment; thus, aggressive management of these risk factors is crucial not only for prevention but also potentially for mitigating initial stroke severity.