Purpose — to assess the etiological significance of herpesviral infection (HVI) in patients with acute idiopathic optic neuritis (ON) using clinical and laboratory monitoring. Material and methods. Clinical and laboratory examinations were conducted for 10 years and were based on the results of etiological monitoring of 79 patients (85 eyes) with acute idiopathic ON in the period of 2005—2015. Results. During a complex examination of 79 patients with acute idiopathic ON, various infectious pathogens were diagnosed in 75 people (94.9±2.1%). HVI was clearly dominant (69 patients — 87.3±2.4%). These patients were divided into 3 etiological groups. The first group — 34 people with herpesviral monoinfection; the second group — 15 people with mixed viral-viral infections; the third group — 20 people with mixed viral-bacterial infections. In the general population of patients with acute idiopathic ON associated with HVI, herpes simplex virus-1 is the most frequent (by more than 2.5 times), the infections of Epstein—Barr virus and cytomegalovirus were detected less often (p<0.05). Active current HVI in the general group of patients was diagnosed in 58 patients (84%). At the same time, reactivation of chronic infection (79.7%) was noted to be prevalent, while primary acute HVI was diagnosed rarely (4.3%). The remaining 11 patients (16%) had chronic persistent HVI. Conclusion. Clinical and laboratory monitoring of HVI in patients with acute idiopathic ON has shown the etiological role of herpesviruses in its development. Based on a complex of serological markers in enzyme-linked immunoassay reactions of blood serum, it was found that in patients with acute idiopathic ON the frequency of herpesviral infection is 87.3±2.4%. The proportion of active (etiologically significant) herpesviral infection is 84% of the total group. The results of the clinical and laboratory studies are of great practical importance for verification of the etiologic diagnosis and selection of adequate etiopathogenetic therapy in patients with acute idiopathic ON associated with HVI.