Background <p>This study aims to investigate the morphometric and volumetric characteristics of the lateral ventricles in relation to age and gender using magnetic resonance imaging (MRI).</p> Materials and methods <p>A total of 212 subjects (106 males, 106 females) underwent 3 Tesla MRI scanning. Axial T2-weighted images were analyzed using Myrian 2.7.1 software. Measured parameters included ventricular length, width, volume, anterior horn distance, and brain width. Ratio indices—ventricular width/hemisphere width and anterior horn distance/brain width—were also calculated. Statistical analyses were performed using SPSS v26.0 with appropriate parametric and non-parametric tests.</p> Results <p>The volumes (cm³), lengths (mm), widths (mm) of the ventricles were measured as follows: in females, 5.13–4.54, 69.10–66.85, 8.35–8.23, and in males, 5.51–4.92, 66.10–64.80, 8.95–8.67 (left–right). No significant gender differences were observed in ventricular volumes, lengths, and widths (<i>p</i> &gt; 0.05). However, significant age-related variations were noted in these parameters (<i>p</i> &lt; 0.001), with moderate positive correlations identified between the width/hemisphere ratios of both right and left ventricles and their respective volumes, as well as between the anterior horn’s distance/brain width ratio and total ventricular volume (<i>p</i> &lt; 0.001).</p> Conclusions <p>Lateral ventricular enlargement was clearly age-related, especially in older individuals. Sex showed limited impact on ventricular morphology. Ratio-based metrics proved useful in proportionally reflecting ventricular changes and may serve as reliable tools in clinical neuroimaging. This study offers normative data on lateral ventricle size in a Turkish population using standardized 3T MRI protocols. The findings may assist in distinguishing normal aging from pathological enlargement and support the use of ventricle-to-brain ratios in clinical evaluation.</p>