Introduction: Vertebral artery hypoplasia (VAH) is a common variation; however, its role in posterior circulation stroke (PCS) has not been fully elucidated. Thus, this study aimed to evaluate the relationship between VAH and PCS with clinical and laboratory parameters. Methods: Between January 2016 and June 2020, 178 patients with PCS who were hospitalized in the neurology department were included. The demographic characteristics, vascular risk factors, stroke patterns, and the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores of patients were recorded. Patients with VA diameter of ≤2.0 mm or 1:1.7 ratio difference in computed tomography angiography were included in the VAH group. Results: This study included 115 females and 63 males. The mean age of patients was 65.8±12 years. VAH was determined in 74 (41.6%) patients, whereas none in 104 patients (58.4%). No significant difference was determined in terms of gender and age in patients with and without VAH (p=0.310 and p=0.676, respectively). No statistically significant difference was found between the two groups in terms of vascular risk factors (p>0.05). Lacunar stroke pattern was less frequently found in patients with VAH (p=0.045). Other stroke patterns were similar in both groups (p>0.05). The NIHSS (p=0.01) and mRS (p=0.018) scores were significantly higher in patients with VAH than those without. Conclusion: The presence of VAH in PCS may adversely affect the clinical severity.