Life-time prevalence of nonsuicidal self-injury (NSSI) has consistently been found to be around 17% in community samples of adolescents. Concerns of threats to mental health in adolescents during covid-19 have been raised. Life-time prevalence of NSSI in high school students in Sweden was compared using the same item to assess NSSI at three different time points. Results showed very similar prevalence of NSSI in 2011 and 2014 (17.2 % vs. 17.7 %), and an increase to 27.6 % during the pandemic of 2020-2021. Our findings imply a need to highlight the potential psychosocial consequences of covid-19 for young people.