Two adult patients with a background history of astrocytomas treated with resection and cranial irradiation, 18 and 16 years previously, presented with acute onset of headache associated with prolonged neurological deficits, including dysphasia and right hemiparesis. The first patient also developed seizures while in hospital. In both patients, magnetic resonance imaging brain scans failed to show evidence of acute ischaemia or tumour recurrence and symptoms reversed completely after 1 month and 7 days, respectively. A single photon emission computed tomography scan, performed on the first patient at day 8 post-admission, showed hyperperfusion in the left parieto-occipital region (in the same region as his previous tumour). The clinical histories and outcomes are consistent with the diagnosis of post-cranial irradiation syndrome with migraine-like headaches and prolonged and reversible neurological deficits. Recognition of this disorder is useful in providing reassurance of a favourable prognosis and may also help avoid invasive investigations.