A releasable port connection assembly comprises a female port member having a tubular passageway extending in an axial direction, a male connector having a tube connection end for connecting a tube to it, and a port connection end configured to be received and retained in the tubular passageway by a retaining pawl arrangement configured to engage an outwardly projecting locking shoulder on the port connection end of the male connector once the male connector has been inserted into the tubular passageway and its locking shoulder has passed the protrusion, characterized in that the protrusion is formed as a circumferentially extending inner rim of an elastically deformable split ring which is slidably received between sidewalls of a circumferential groove formed in an inner wall of the tubular passageway.