To characterize the effect of oxidative stress (OS) on the ability of erythrocytes to pass through microvessels and capillaries, we studied the dynamics of the movement of human erythrocytes in vitro, in the channels of a microfluidic device, under the action of an OS inducer, tert-butyl hydroperoxide (tBH), and compared it with a cytological assessment of the transformation of cell membranes. OS induced the impairment of the control over the shape and volume of cells, the decrease in passage speed, and the occlusions of microchannels. The developed microfluidic device provided an assessment of the microreology of erythrocytes under the action of hydroperoxide. In the future, it is possible to use microfluidic analysis of erythrocytes in patients to assess the effect of xenobiotics on microrheology.