Radiological explorations of the thorax raise a certain number of risks for the mother and infant which should be well recognized by the pneumologist. Irradiation is the major risk and can be evaluated in comparison with other risks of radiation. We recall the dosimetric system based on the effective dose expressed in Sievert (Sv). The risks of irradiation are described. The dangers related to contrast agents are discussed. Each type of thoracic imaging is then considered from the standpoint of the technique, risks involved and means of radioprotection. Precise indications for each technique are given in detail for pregnant women. We review rapidly the physiological and pathological signs and symptoms observed during pregnancy and propose a practical attitude for ordering radiographic explorations.