Erythrocytes change their micromechanical properties associated with membrane viscoelasticity when they perform the transport function. There is some evidence that this is due to the influence of signaling molecules, including such gasotransmitters as nitrogen oxide (NO) and hydrogen sulfide (H2S). The aim of this study was to investigate the changes in microrheology of human erythrocytes under the influence of donors and stimulants of endogenous formation of gasotransmitters. The erythrocyte deformability, assessed by the elongation index of erythrocytes (EIE), and aggregation parameters, the indices of aggregation of erythrocytes (IAE), of washed cells were recorded after their incubation with sodium nitroprusside (SNP); sodium hydrosulfide (NaHS), the donor of H2S; 1H-[1,2,4]-oxadiazolo [4,3-a] quinoxalin-l-one (ODQ), an inhibitor of soluble guanylate cyclase; L-arginine and N-nitroarginine methyl ester (L-NAME), a substrate and an inhibitor of NO synthase, respectively; and glibenclamide (GBC ), the blocker of ATP-sensitive potassium channels. In addition, the resealed ghosts of erythrocytes were prepared, incubated with the above compounds, and the change in their deformability was evaluated. EIE increased by 8–11% (p < 0.01) and IAE decreased by 11–26% (p < 0.01) after the incubation of erythrocytes with SNP and NaHS, respectively. L-arginine and SNP exerted similar microrheological effects, which were eliminated by L-NAME or ODQ. GBC caused an increase in EIE by 8% (p < 0.05); the effects of GBC and NaHS were not additive. Incubation of the erythrocyte ghosts with SNP, L-arginine and NaHS was accompanied by a moderate but significant increase in membrane elasticity (p < 0.05). The obtained results indicate that the donors and stimulators of gasotransmitters NO and H2S moderately increase deformability of erythrocytes and markedly reduce their aggregability. The experiments on the erythrocyte ghosts suggest the existence of a direct effect of gasotransmitters on the viscoelastic properties of the membrane of these cells, which is independent of cGMP.