Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system characterized by multiple disseminated lesions. The pathogenesis of this disease is still insufficiently clarified, and the course of the disease is unpredictable. It happens that severe relapses do not respond to drug therapy and in such cases it is recommended therapeutic plasma exchange (TPE). We present a young man with severe motor relapse, weakness of the left leg, pronounced tremor of the right arm, unstable gait and bilaterally reduction of vision. Brain magnetic resonance imaging showed a large number of chronic demyelinating lesions of the white mass, numerous were merged, with signs of brain reduction. The patient underwent five cycles of TPE, which were conducted every other day. Although TPE led to a disturbance of the hemostasis status and some biochemical parameters, the patient’s response to the applied therapy was good. The improvement of the patient’s condition was reflected through the return of vision and a moderate reduction in neurological deficit. Despite the fact that therapeutic plasma exchange can cause some complications, it should be considered when drug therapy does not lead to improvement in these patients.