The invention relates to a method for determining the viability of cells in cell cultures, said method comprising the steps of: coloring the sample with a dye which can penetrate into individual cells depending on the viability of the latter, determining the proportions of cells which are colored to differing extents. The invention is distinguished by virtue of the fact that a cell suspension of the colored cells is centrifuged as a sample in a sample vessel (10) until the solid content present in the sample has settled as a compressed cell cake (13), and, in order to determine the proportions, the volumes of differently colored sections (131, 132, 133) of the compressed cell cake (13) are determined as a measure of the proportions of cells of different viability.