A description is given of a device (10) for the connection of branch pipes (2) to a main pipe (1) in irrigation systems comprising an elastic clamp (11) carrying a hollow pin (13) with a pointed end (15) suitable for perforating and arranging itself inside the pipe (1), and having an outer section (17) for the fitting of a branch pipe (2), the clamp being open on the side opposite to the pin (13), where series of opposite teeth (22), (24) are provided, suitable for allowing the tightening and not the widening of the clamp (11).