Abstract: Algorithms of cell segmentation on two-dimensional phase images and three-dimensional distributions of a refractive index obtained by means of digital holographic microscopy and tomography are developed. The proposed algorithms are optimized for determining cell morphology characteristics including the cell volume, projection area, and surface area. A comparative analysis of the error of cell volume determination by holographic methods using the proposed cell segmentation algorithms and the standard method of confocal fluorescence microscopy has been performed.