SummaryBackgroundAgenesis requires an extensive work-up as a number of associated other vascular and nonvascular anomalies can be expected. In this scenario, an associated ipsilateral basal ganglia bleeding with subarachnoid haemorrhage with no aetiology is uncommon. We present such a case of moderate ipsilateral ganglio-capsular bleed of unknown cause with associate aortic arch vessel anomaly.Case ReportA 45-year-old diabetic man of Indian origin with complaints of a sudden onset of giddiness, left-sided weakness and slurring of speech. Motor system examination revealed power of grade 2. Computed tomography scan revealed a moderate bleeding in the basal ganglia and the right temporo-parietal lobe. Angiography revealed unilateral aplasia of the internal carotid artery.Patient improved symptomatically with a motor system power of grade 4 after hematoma evacuation and treatment with antibiotics, anti-edema measures and neuroprotective drugs.ConclusionsDevelopmental anomalies of the carotid and aortic arch with intracranial bleeding is a rare occurrence and any arterial anomaly requires extensive evaluation.