The article describes a complex study of detonation nanodiamonds (DND) aqueous dispersions. In this research, DND sample was characterised by means of IR, NMR spectroscopy, TEM, thermogravimetric analysis, size distribution, and ζ-potentials. It was shown that DND sample includes several surface groups, mainly hydroxylic, carboxylic, and carbonyl ones. Dynamic light scattering results revealed that in the concentration range C = 0.002–0.3 wt%, DND nanoparticles size is equal to 55 ± 5 nm. It was demonstrated that DND possessed weak antiradical activity, had an inhibitory effect on F₁F₀-ATPase activity, almost did not affect platelet aggregation, formed a stronger complex with human serum albumin (HSA) in subdomain IB (digitoxin, K_b = 20.0 ± 2.4 l·g⁻¹) and a less strong complex in subdomain IIA (warfarin, K_b = 3.7 ± 0.1 l·g⁻¹), inhibited the esterase activity of HSA, DND dispersions (C = 0.0012–0.15 wt%) revealed genotoxic effect towards PBMCs, did not affect cellular proliferation in the experiment with HEK293 cell line, did not reveal cytotoxic effect up to 0.01 wt%. Using DFT and MD approaches allowed us to perform a simulation of interaction between DND nanoparticle and water molecules.