The goal of this study was to analyze the relationship between stressors (frequency of and reaction to disruptive behaviors), cognitive fusion and ambivalence among caregivers, and more specifically to study whether cognitive fusion acts as a mediator in the relationship between stressors and ambivalence. To assess these variables, individual interviews were conducted with a total of 364 caregivers of a relative with dementia. Significant and positive correlations were found among stressors, cognitive fusion and ambivalence (p< .05). The model suggests that there is a significant and positive relationship between reaction to disruptive behaviors and ambivalent feelings among caregivers, although it seems to be mediated by cognitive fusion. The final model explains 37% of the variance of ambivalence, and it shows an excellent fit to the data. The results suggest that the relationship between frequency of disruptive behaviors and ambivalence seems to be mediated by reaction to disruptive behaviors and cognitive fusion; consequently this last variable seems to be relevant for understanding emotional ambivalence among caregivers.