Abstract: A method and an installation for controlling the filling of containers (5) with a flowable product in a filling installation has a product reservoir (1) and a filling unit (3) for simultaneously filling several containers (5). The method consists in: measuring the total real flow rate of product delivered by the filing unit (3) to the whole set of containers (5); detecting the number n of containers (5) being filled in the filling unit (3); displaying a theoretical flow rate q of the individual filling of the containers (5); comparing the total real flow rate measured and the theoretical flow rate n.q; and, correcting, if necessary, the total real flow rate to make it coincide with the theoretical flow rate. The operation of the installation is thereby adapted to the exact number of containers being actually filled simultaneously, with no significant variations of real individual filling flow rates.