Abstract: A patient interface assembly has a patient interface and a securement system for the patient interface and/or patient interface tubing. The patient interface has a body and at least one nasal prong extending from the body. The at least one nasal prong has a gas inlet for fluid communication with a supply of breathable gas, and a gas outlet configured to direct a flow of gas towards a nare of the user's nose. The at least one nasal prong further includes an exterior surface, at least a portion of the exterior surface is a sealing surface configured to seal the nare of the user's nose. The securement system has a two-part releasable attachment or connection arrangement, the arrangement comprising a first patch and a second patch.