A plasma tank is a storage vessel for plasma. Damage to the tank or a plasma conduit connected to it can be a serious condition if the fire resulting from such damage cannot be put out with a fire extinguisher.

In 2370, Kira Nerys and Jadzia Dax were forced to jettison the plasma tank of their Bajoran raider shortly before it crashlanded. This was due to weapons fire from other Bajoran vessels controlled by members of the Alliance for Global Unity. (DS9: "The Siege")