Convexity subarachnoid haemorrhage (SAH) has many possible causes. A 76-year-old man presented with back pain, left leg weakness, and hypertension. His brain imaging showed convexity SAH, with additional intraventricular blood and extensive spinal SAH from T3-S2. Following deterioration from a probable further haemorrhage, with development of left foot myoclonus, a spinal digital subtraction angiogram was normal but cerebral angiogram identified a cerebral dural arteriovenous fistula, which was successfully embolised. Convexity SAH has a heterogeneous clinical presentation and dural arteriovenous fistula is a potential cause.