Background Parents of adolescents with mental disorders experience stress partially due to the way they perceive and experience their offspring's disorder. The current study assessed the mediator role of self-stigma in the relationship between insight into the disorder and parental stress of parents of adolescents with mental disorders. Method A total of 37 parents of adolescents with psychiatric disorders were assessed for their level of insight, self-stigma and parental stress. Results The hypothesized mediation model was confirmed and is consistent with previous study on parents of adults with severe mental illness. Discussion The positive association between insight and parental stress is mediated by these parents' self-stigma, suggesting that insight increases the self-stigma, which in turn increases the parental stress. These results may have clinical implications with regard to the treatment of the family of adolescents with mental disorders.