Reversible cerebral vasoconstriction syndrome is characterised by severe thunderclap headache with associated characteristic transient, multifocal, segmental vasoconstriction of cerebral arteries lasting several weeks to months. We describe a 50-years old woman who presented with a severe sudden onset occipital headache. Neuroimaging revealed segmental vasospasm affecting the intracerebral arteries. The pain improved gradually over the next 6 weeks. Repeat brain MR angiography at 12 weeks showed complete resolution of the segmental narrowing.