A collapsible respiration bag assembly is disclosed and includes a flexible hollow body longitudinally extending about a longitudinal axis thereof between an air intake end and an air outlet end and formed with at least three annular folds. A patient valve is fitted at the outlet end and includes a face mask coupler transversing the longitudinal axis. An intake valve assembly is also included and a face mask fitted with a face engaging rim, a dome portion and a valve coupler detachably connectable to the face mask coupler. The dome portion of the face mask is deformable between an operative, concave position and a convex stowing position, where the dome portion is inverted and where the valve coupler is detached from the face mask coupler. The assembly is configurable between at least one extended, operative position and a fully collapsed stowed position where the annular fold zones at least partially overlap.
