The study investigated the relations between body dissatisfaction and emotional dysregulation. This is the first research focusing on the mediating effect of emotional dysregulation on the relationship between negative affect and body dissatisfaction in a Russian female population. It is particularly relevant given that both emotional dysregulation and body dissatisfaction may lead to the emergence of psychopathological symptoms (e.g., depression, self-injurious behavior, and eating disorders). 778 girls and women aged 14–40 years (M=19,8; SE=3,31) participated in the study. The following measures were used: Body Image Questionnaire (Skugarevsky, 2006), Emotional Dysregulation Questionnaire (Polskaya, Razvaliaeva, 2017), Emotion Regulation Questionnaire (Gross, John, 2003; Russian version by Pankratova, Kornienko, 2017) and Positive and Negative Affect Schedule (Watson et al., 1988; Russian version by Osin, 2012). High level of body dissatisfaction was significantly associated with high scores of rumination, avoidance and difficulties in mentalizing from the Emotional Dysregulation Questionnaire, high level of negative affect and low level of positive affect. Respondents with high body dissatisfaction also preferred expressive suppression to cognitive reappraisal for emotion regulation. Regression analysis showed that negative affect (b=0,20; p<0,001) and emotion dysregulation scales — rumination (b=0,66; p<0,001), avoidance (b=0,69; p<0,001) and difficulties in mentalizing (b=0,33; p<0,001) — significantly predicted body dissatisfaction (F(4, 773)=130,8, p<0,001; R2=0,405; R2adj=0,402). Emotion dysregulation scales mediated the effect of negative affect on body dissatisfaction.