Background Coeliac crisis is a life-threatening presentation of coeliac disease. Severe diarrhoea, weight loss, electrolyte imbalances and malnutrition are prominent features. Although mainly a disease of childhood, it can on the rare occasion be diagnosed in adults. Case presentation A 25-year-old female with severe generalised oedema, lower extremity weakness, hypokalemia and profound hypoalbuminemia was referred with an initial diagnosis of nephrotic syndrome. Three months previously she had given birth to a healthy child following an uneventful pregnancy. She did not have proteinuria. She had a history of diarrhoea with gluten-containing food since childhood but lacked a formal diagnosis of coeliac disease. A duodenal biopsy confirmed the suspected diagnosis. Coeliac crisis was diagnosed with life-threatening multisystem involvement. Introduction of a gluten-free diet abolished all disease symptoms and ameliorated laboratory parameters at six months' follow-up. Conclusion Coeliac crisis is a rare, yet dangerous presentation of coeliac disease in adults. As this case suggests, it can present with generalised oedema and hypoalbuminemia mimicking nephrotic syndrome. Rapid diagnosis is the key to successful treatment.