Background: The cerebral ventricles are fluid-filled cavities within the brain crucial for cerebrospinal fluid (CSF) circulation. Assessing their size is important for diagnosing neurological conditions. This study aims to establish reference ranges for the morphometry (size and shape) of the third and fourth ventricles in healthy Bangladeshi adults using Magnetic Resonance Imaging (MRI). Methods: A cross-sectional study was conducted on 200 healthy adults (100 males and 100 females) aged 18-60 years. High-resolution T1-weighted MRI scans were obtained, and morphometric measurements of the third and fourth ventricles were performed. The parameters measured included the width, length, and height of the ventricles. Statistical analysis was carried out to assess the variations in ventricular dimensions across different age groups and between sexes. Results: The study found that the mean dimensions of the third and fourth ventricles in the Bangladeshi population are consistent with existing data from other populations, with some variations. Significant differences were observed in the dimensions of both ventricles between males and females, with males showing slightly larger measurements. Age-related changes in ventricular size were also noted, with a trend towards increased dimensions in older age groups, indicating possible age-associated atrophy. Conclusion: This study provides valuable baseline data for the third and fourth ventricular dimensions in the adult Bangladeshi population. These normative values can aid in the diagnostic assessment of various neurological conditions and contribute to a better understanding of intracranial anatomical variations in this demographic. Further research with a larger sample size and inclusion of pathological cases is recommended to enhance the clinical applicability of these findings. This study has provided valuable reference data for interpreting ventricle size in Bangladeshi adults undergoing MRI scans. Deviations from these norms might warrant further investigation for potential neurological issues. The findings can contribute to improved diagnosis and management of neurological conditions in Bangladesh.