Irradiation of unknown pregnancy: review of 17 cases. The article summarizes the analysis of 47 cases of pregnant women who did not know their pregnancy and had undergone one or more diagnostic radiological examinations. We distinguished two groups. The first group G1 consisting of 12 women whose exposure to radiation had been focused under diaphragmatic region and occurred during the critical period of organogenesis with a gonadal dose estimated to range 12 to 52 mGy. A therapeutic abortion had been recommended to these women. The second group G2 consisting of 35 women whose exposure to radiation interested directly or indirectly the above diaphragmatic region with dose lower than 10 mGy. To these women, a recommendation to continue their pregnancy had been given. We investigated only 17 pregnant women issues; 7 from G1 et 10 from G2. We noted that there were no spontaneous abortion or major abnormalities or malignant diseases. However, 4 minor abnormalities were identified among the examined children sample: facial dysmorphism, anus atresia, hypospadias and harelip. These anomalies could not be attributed to the irradiation effects because the conceptus received very low doses during the minimal risk gestation period. We believe that the malformations observed may be attributed to congenital malformation risk.