A method for filling a fuel tank with liquefied gas includes liquefied gas being brought into the tank so that gas in introduced to a lower section of the tank below the surface of the liquefied gas in the tank, and during a first phase of the filling procedure while gas is introduced to a lower section of the tank the pressure of the tank is maintained below a predetermined set pressure by spraying of liquefied gas into a gas space in the upper section of the tank above the surface of the liquefied gas in the tank. At a predetermined state of the filling procedure a second phase of the procedure is initiated during which the spraying liquefied gas into a gas space in the upper section of the tank is decreased and the second phase is practiced until a predetermined filling stage of the tank is reached.