Propyliodone (INN, trade name Dionosil) is a molecule used as a contrast medium. It was developed by a team at Imperial Chemical Industries in the late 1930s. Propyliodone used as radiopque medium for brochographic use. When directly instilled into the bronchi resulting in well-defined bronchograms for atleast 30 min. Because of its toxicity, Propyliodone should only be used if absolutely essential. It is of Synthetic origin and belongs to Iodinated Radio-opaque Compounds. It belongs to Radiopaque Agents pharmacological group on the basis of mechanism of action and also classified in Diagnostic Aids pharmacological group. Oral absorption of Propyliodone is found to be 101% and metabolism is reported Lungs and Gut wall. Propyliodone is primarily indicated in conditions like Paget's disease of bone, Radiological contrast agent. Propyliodone produces potentially life-threatening effects which include Fever, Anaphylaxis, Repiratory obstruction, Cerebral embolization, which are responsible for the discontinuation of Propyliodone therapy. The signs and symptoms that are produced after the acute overdosage of Propyliodone include Airway obstruction. The symptomatic adverse reactions produced by Propyliodone are more or less tolerable and if they become severe, they can be treated symptomatically, these include Headache, Fever, Malaise, Nausea and vomiting, Aching joints.