An injection site for medical lines includes a tubular body made of molded plastic material within which an elastic element made of thermoplastic material is overmolded on an enlarged end of the tubular body. The enlarged end delimits an inner annular flange and is formed with at least one radial through-hole through which the elastic element is overmolded in order to rest axially against the inner annular flange and fill the radial through-hole with an appendage.
