Computed tomography angiography (CTA) is a non-invasive procedure to evaluate vascular anomalies. However, the high radiation dose related to the examination is a concern due to its associated cancer risk. Therefore, this study aims to investigate the effect of low tube voltage CT cerebral angiography (CTCA) on radiation dose and image quality based on body mass index. Eighty patients were included in this study, where an initial 20 patients were scanned with standard dose protocol, irrespective of BMI. The remaining 60 patients were equally allocated to BMI-based protocol, where high and obese BMI was allocated to 120 kVp protocol, normal BMI to 100 kVp protocol, and low BMI to 80 kVp protocol. Dose data and image quality data were collected after the scan. The result showed a 65% reduction in radiation dose, a 40% increase in vessel attenuation for the 80 kVp protocol, and an improved qualitative image score. In conclusion, tailoring the tube voltage with BMI can be used for CTCA while achieving significant dose re-duction without compromising image quality.