The aim of the study was to determine the clinical and psychopathological characteristics of non-suicidal self-injury (NSSI) in personality disorder (PD) in the comparative age-related aspect during the coronavirus infection (COVID-19) pandemic. Patients and methods: a total of 230 patients (177 males and 53 females) aged 16–25, diagnosed with PD and NSSI behavior manifestations, were studied retrospectively in mental hospital and outpatintly by using clinical-psychopathological method. All patients were divided into two equal groups of 115 people each. Group I was examined in 2017–2019, Group II — in 2020–2021 during the coronavirus infection (COVID-19) pandemic. Results: common features established in both groups were as follows: affective instability, alexithymia, conflict relations with significant others, and current traumatic experience. For a comparative assessment of NSSI in patients of both groups, we used the NSSI typology in adolescent PD, previously developed by the authors. Impulsive, demonstrative, addictive, depersonalizing and self-destructive types of NSSI were recognized as significant for the diagnostic assessment. In the second group of patients, that is, during the period of the COVID-19 pandemic, a change in the selected variants of NSSI was found, that is, in borderline and narcissistic PD the impulsive type was replaced by a demonstrative type, and in schizoid and anxious PD it turned into an addictive one. For a comparative assessment of NSSI in patients of both groups, we used the NSSI typology in PD in adolescence, previously developed by the authors. When assessing suicidality in group II, it was revealed that in most types of PD, with a decrease in the number of suicidal attempts, there was a noticeable increase in the incidence of NSSI with demonstrative suicidality, which correlated with the trajectories of the identified variants of NSSI. Conclusions: the study underlined the role of personality pathology in in adolescence in the development of psychopathological disorders with NSSI and their high association with suicidal activity. The modification of various NSSI variants in the context of a coronavirus infection (COVID-19) pandemic may be due to the unique characteristics of the psychotraumatic factor. With the same strength of impact, the multidirectional influence on various personality types and comorbid psychopathological disorders in adolescence should be taken into account, when creating new models of therapeutic and socio-rehabilitation interventions for the adolescent contingent of patients.