A 74-year-old gentleman presented with an acute onset of confusion and agitation. His symptoms were so severe that he had to be sedated and intubated for CT scan. All investigations were unremarkable, except a low serum phosphate. He was treated with intravenous phosphate and his symptoms improved in line with the rise in his serum phosphate. By discharge, he had returned to his previous state of health. The cause of the hypophosphataemia was not apparent; we have asked his general practitioner to monitor his serum phosphate.