SummaryA case of intermittent acute porphyria occuring immediately after pregnancy is described in a female of 25, up to then in good health. The clinical symptomatology was characterised by acute abdominal crisis with vomiting and constipation, hypertension periods with uremia, a severe extensive and progressive polyneuritis appearing on a very peculiar mental background made of hysteria and melancolia.The biochemical study of urine has shown the constant presence of large amounts of porphobilinogen and uroporphyrin III (up to 3,5 mgr. per day), of uroporphyrin I (up to 1,7 mgr. per day), of coproporphyrin (150 to 200γper day).The patient’s mother, although otherwise healthy shows a comparable urinary syndrom, but with a lesser excretion of uroporphyrin. The patient’s sons present an unconstant excretion of porphobilinogen. These facts confirm the hereditary character of the disease. Finally the authors discuss the physiopathology of porphyrinuria, and its relationship with the metabolic and endocrinologic modifications shown by the patient.