An instantaneous connection device includes a tubular body and a tight element which is used to hold the end of a line in the body and includes a holding element arranged to receive the end of the line and a cam element arranged between the body and the holding element and used to move the holding element from a free state into a state wherein it grips the end of the line when it is axially displaced in the tubular body between a first position and a second position. The holding element includes two jaws independently mounted in the body so as to slide between the two positions, and the cam element includes two transversal pins that are fixed to the jaws or body so as to slidingly co-operate, with transversal surfaces fixed to the body or the jaws and inclined in relation to the sliding direction.
