Abstract: A tip-safe chest drainage unit provides liquid sealed chest drainage. The unit has an enclosure of unitary form constructed of synthetic resin material, defining various chambers including a liquid seal chamber, a drain fluid collection chamber, manometric chambers and various equilibration and relief chambers. A chest drainage tube extends into the seal chamber, which is configured for being normally substantially filled with liquid for submerging the end of the drain tube to provide atmospheric sealing thereof. The fluid collection chamber communicates with the seal chamber for receiving fluids via the seal chamber resulting from chest drainage through the drain tube. The equilibration chambers and various baffles in the enclosure preserve fluid content upon tipping of the unit to maintain the drain tube end submerged in fluid at all times.