Abstract: A bag for packaging liquid formed using plastic in film form is disclosed. The bag includes a leaktight chamber for liquid and a pocket, adjacent to the chamber, in which a pipe for withdrawing the liquid is housed. Access is provided to the inside of said pocket. An opening is formed through part of the wall of the pocket, adjacent to the chamber, to allow the withdrawing pipe to enter the chamber in a leaktight fashion. The opening is situated at the end of a tubular element of decreasing section, at the place where the section is the smallest with the element being formed from a film of plastic forming one wall of the pocket adjacent to the chamber. The tubular element accommodates the pipe for withdrawing the liquid from the chamber and is at least equal to that of the opening, so that the tubular element forms a seal around the withdrawing pipe.