This study examined the mediating role of affect regulation among attachment, negative mood, and interpersonal problems. Participants were 229 college students at a large midwest university. Structural equation modeling indicated attachment anxiety and avoidance contributed to negative mood and interpersonal problems through different and distinct affect regulation strategies (i.e., emotional reactivity or emotional cutoff). The association between attachment anxiety, negative mood, and interpersonal problems was mediated only by emotional reactivity (not emotional cutoff). Conversely, the association between attachment avoidance, negative mood, and interpersonal problems was mediated only by emotional cutoff (not emotional reactivity). Furthermore, emotional reactivity and emotional cutoff explained 36% of the variance in negative mood; attachment, emotional reactivity, and emotional cutoff explained 75% of the variance in interpersonal problems.Attachment theory (Bowlby, 1969(Bowlby, , 1973(Bowlby, , 1980(Bowlby, , 1988 represents an important theoretical perspective for understanding an individual's experience of negative mood and interpersonal problems. The basic premise of attachment theory is that individuals' emotional experiences with primary caregivers lead to the development of attachment security or insecurity. Attachment security or insecurity is then associated with the individuals' ability to connect with others and cope with affective or stressful problems (e.g., Kobak & Sceery, 1988). If individuals have caregivers who are consistent in their emotional availability, they are likely to develop attachment security and can effectively cope with negative events that arise in their life (e.g., seek support from a friend). If individuals do not have caregivers who are emotionally available, individuals are likely to develop attachment insecurity and subsequently be less able to cope with stressful events in their lives (e.g., withdraw from others).Brennan, Clark, and Shaver (1998) recently indicated that adult attachments could be described in terms of two orthogonal dimensions: attachment anxiety and attachment avoidance. Adult attachment anxiety is defined as the fear of rejection and abandonment. Adult attachment avoidance is characterized as the fear of intimacy and discomfort with closeness and dependence. In the attachment literature, it is well documented that the presence of these attachment dimensions are positively linked to indices of psychological distress such as depression and anxiety (e.g.,