Abstract: A pouch-like bag for containing a liquid for medical or surgical use has two walls (10, 11) formed by respective plies of flexible plastics material sealed together (at 12) around at least their top and side edges and one or more, folded plies (14) of flexible plastics material of substantially smaller dimensions forming a gusset bottom portion having opposed leaves (16, 17) each of which is sealed (at 18) to the adjacent wall (10, 11). The gusset ply (14) carries one or more elements (21, 22 ) of elastomeric material capable of making an hermetic and liquid-tight seal with a needle, e.g. an administration set needle for a hospital drip-feed system or a hypodermic or injection needle for injecting a drug into the bag contents.