This paper investigates the effect of different concentrations of nanostructured materials: fullerene-like (C60), onion-like carbon (OLC) and ultradispersed diamonds (UDD) on the formation of multicellular spheroids. The chemical composition and purity of nanomaterials are controlled by Fourier transform infrared spectroscopy. The strength and direction of the impact of nanomaterials on the cell population was assessed using microphotography of tumor multicellular spheroids of breast adenocarcinoma cell line MCF-7 in vitro and Pearson's correlation coefficient. The results demonstrated that UDD and OLC reduced adhesion and cohesive ability of cells and stimulated generation of cell spheroids of ∼3 × 10−3 mm3 in significant amount. The fullerenes reduced in the main cell adhesion to substrate that led to formation of cell aggregates of ∼5 × 10−3 mm3. The results could be useful for achievement of the directed cell growth in three-dimensional culture.