Acute intermittent porphyria is an autosomal dominant condition caused by a genetic defect of the deaminase gene located on the 11. chromosome. Due to this defect only 50% of the normal enzyme quantity is produced. The disease becomes manifested only in the case of increased demands on given metabolic pathway resulting in porphobilinogen accumulation and storage in the organism. Clinical pattern involves abdominal, neurologic and psychiatric symptomatology. Laboratory diagnosis is based on the detection of delta-aminolevulinic acid, porphobilinogen, uroporphyrin and coproporphyrin in the urine. Between the attacks may only the detection of porphobilinogen deaminase in erythrocytes, leukocytes and skin fibroblasts be positive. The therapy is based on infusions of 20% glucose solution and hydromineral imbalance correction. When neurologic symptoms occur it is necessary to administer hem-arginate intravenously. The case report presents almost textbook case of a young female patient suffering from the disease. (Ref. 7.)