BACKGROUND:Acute intermittent porphyria is the most common type of porphyria occurring in Poland. Its characteristic feature is periods of remissions and aggravations. Aggravation or an attack of the disease is caused by many endogenous and exogenous factors, among others by hormonal contraceptives. CASE REPORT:This article describes the case of an acute intermittent porphyria attack in a 28 years old female patient resulting from the use of a few, contraindicated drugs (metamizole, nospa, desogestrel in case of porphyria, urinary tract infection, as well as a spontaneous abortion two months earlier). The attack included abdominal pain, vomiting, reduction in muscle strength in limbs and it was complicated by seizures caused by hyponatraemia. High excess haem precursors in urine was observed. During hospitalization, the patient ceased to take harmful drugs and she was given haem arginate, glucose and symptomatic drugs, and she recovered completely. CONCLUSION:In the described case there were a few porphyrogenous factors whose action was observed, among which the most important was desogestrel. Due to this conclusion, a change in contraceptive therapy that would exclude hormonal contraception was suggested.