The diagnosis of porphyria remains challenging as the condition is characterized by a myriad of clinical and biochemical features. More importantly, an acute attack is associated with increased morbidity and mortality. Misdiagnosis of porphyria poses an ongoing problem. We describe a 42-year-old Black female South African patient who presented to Steve Biko Academic Hospital in Pretoria, on the 16 July 2014 with a clinical problem of acute paraparesis. On admission, she had absent reflexes, bilateral cranial nerve VII fallout, patchy sensory fallout and faecal incontinence. When her magnetic resonance imaging of the brain and cervical spine showed no signs suggestive of acute disseminated encephalomyelitis, a diagnosis of Guillain–Barré syndrome was made. On the 21 July her condition deteriorated to the point where she needed ventilator support. She also developed a pulmonary embolism and was treated. Due to deterioration of her condition, urine was sent for porphobilinogen test. This was clearly positive. The diagnosis of acute intermittent porphyria was eventually made. This case highlights the complexity related to the diagnosis of porphyria. It confirms that the diagnosis is often incidental and in a vast majority of patients, neurological complications preceded the final biochemical diagnosis.