The basic principles of High Pressure Low Temperature treatment (HPLT) of foods have been extensively explored in several studies over the last decade. Research activities in this field mostly focused on the inactivation of microorganisms, textural damage in plant and animal tissue and mechanisms behind nucleation and ice formation. Of central concern in the present study is the effect of High Pressure Low Temperature treatment on the properties of dairy based, emulsified frozen food foam and the equivalent non aerated liquid system. Special emphasis was put on the freezing behavior under pressure, sensorial properties, the air cell distribution and ice crystal size and distribution. A phase diagram was modeled on the base of atmospheric pressure DSC data and freezing and melting points determined at atmospheric and high pressure conditions.