A case of initial presentation and diagnosis of hereditary coproporphyria is described, following a patient's first seizure in the surgical ward, where she had been admitted for investigation of abdominal pains. The frequency of seizures, motor neuropathy and florid visual hallucinations worsened over the subsequent days, until the definitive investigations revealed the diagnosis and specific therapies were instituted. The acute porphyrias, a rare group of conditions caused by deficiencies in enzymes involved in haem biosynthesis, are associated with significant morbidity and occasional mortality. Consideration of the diagnosis, combined with appropriate supportive and specific therapies can reduce the duration of the crisis and lessen the rates of morbidity and mortality associated with these conditions.