Introduction. Perfectionism is currently considered as one of the transdiagnostic processes. It has been shown that perfectionism interferes with adaptive emotional regulation and is involved in many psychological disorders. According to Hewitt and Flett's perfectionism model, the two dimensions of perfectionism potentially involved in emotional regulation are: (1) Socially Prescribed Perfectionism (SPP), and (2) Self-Oriented Perfectionism (SOP). The research suggests that SPP affects directly not only emotional regulation but also the psychological disorders, particularly depression. SOP seems to interact with other risk factors to predict psychopathology. A broad range of studies suggest that the link between perfectionism and emotional regulation or psychological disorders can be mediated by repetitive negative thinking. Most of the studies have used the conceptualization of repetitive negative thinking as depressive rumination. Yet, recent studies that refer to a new transdiagnostic conceptualization of repetitive negative thinking - the processing mode theory - have not fully explored the interactions between intra- and interpersonal perfectionism and repetitive negative thinking. Nevertheless, preliminary results suggest that an unconstructive processing mode resulting in abstract analytic thinking might play a mediating role in the relationship between perfectionism and psychological disorders. The objective of the present study was to explore how intra- (SOP) and interpersonal (SPP) perfectionism affect emotional reactivity following the experience of failure and if unconstructive repetitive thinking could mediate the link between the two. Method. Forty-four undergraduate students from Lille Nord-de-France University underwent a failure induction task. Their emotional reactivity was measured using Positive and Negative Affect Schedule (PANAS). The scores of positive, negative, dysphoric and anxious reactivity were calculated by regressing post-induction scores from PANAS on the corresponding pre-induction scores. The participants completed questionnaires assessing their perfectionism (Hewitt's Multidimensional Perfectionism Scale) and repetitive thinking mode (Mini Cambridge Exeter Repetitive Thought Scale). Results. The results suggested that both SOP and SPP were correlated with general negative reactivity and with dysphoric reactivity, but only SOP was correlated with anxious reactivity. Mediation analyses were computed with PROCESS, using bootstrapping method. According to the analysis, the link between the SPP and negative emotional reactivity was mediated by abstract analytic thinking, b=0.01, CI [0.01; 0.04] with a medium effect size of κ2=0.10 (95% CI [0.01; 0.27]). The link between the SOP and negative emotional reactivity was also mediated by abstract analytical thinking, b=0.02, CI [0.01; 0.05] (κ2=0.12; 95% CI [0.01; 0.34]). We have observed the same pattern of results for the link between the SPP and dysphoric reactivity as well as for SOP and dysphoric reactivity; both being mediated by abstract analytic thinking, respectively b=0.02; CI [0.01; 0.05] (κ2=0.13; 95% CI [0.03; 0.30]) and b=0.02, CI [0.01; 0.06] (κ2=0.16; 95% CI [0.02; 0.38]). Abstract analytic thinking did not appear to be a significant mediator of the link between SOP and anxious reactivity (b=0.007; CI [-0.006; 0.46]) nor between SPP and anxious reactivity (b=0.002; CI [-0.005; 0.019]). Discussion. The present study suggests that both intra- and interpersonal dimensions of perfectionism are associated with an increase in negative emotional reactivity after experiencing failure. Only intrapersonal perfectionism appeared related to anxious reactivity. In addition, the link between perfectionism and dysphoric reactivity seems to be mediated by abstract analytic thinking. The link between intrapersonal perfectionism and anxious reactivity seems to be independent of repetitive thinking. The results presented above provide a perspective of the differential impact of intra- and interpersonal perfectionism on emotional regulation, but also a clinical perspective of potentially applying rumination-focused therapies to deal with perfectionism in dysphoric individuals.