SummaryThe case of a patient who developed acute pulmonary edema within one hour following intravenous drip infusion of methylglucamine iothalamate is presented, and the possible coexistence of haemodynamic and noncardiogenic (toxic) mechanisms is proposed. Review of the literature of the last decade indicates it to be an unfrequent occurring condition, which however should be considered especially in patients unable to cope with osmotic overloading and with limited cardiocirculatory reserve. Hypertonicity—and not sodium content—was responsible for the circulatory overload in this patient.