This paper describes the clinical case of a 2-year-and-11-month-old child presenting with vomiting, fever, abdominal pain and macrohematuria, alongside clinical signs of jaundice and acute haemolytic anaemia. Initial blood tests and thorough history revealed a favism-induced haemolytic crisis, triggered by fava bean ingestion. The child’s condition improved following red blood cell transfusion. Favism is caused by glucose-6-phosphate dehydrogenase (G6PD) deficiency and is often asymptomatic until oxidative stress occurs. Diagnosis relies on clinical evaluation and detailed dietary and pharmacological history. The only effective treatment is the prevention of exposure to oxidative agents.