Attachment theory was developed by Bowlby (1980) to explore the propensity of humans to make strong affectional bonds with significant others and to explain the different forms of emotional distress experienced when these relationships are disrupted. The concept of adult attachment is commonly employed in empirical studies of psychological interventions. One such intervention that significantly increases wellbeing is mindfulness. Mindfulness diminishes the extent to which circumstances are judged as positive or negative. Therefore, mindfulness might decrease the extent to which working models, primed by feelings of threat, are activated. To quantify what effect mindfulness has on wellbeing, the current study explored the relationship between adult attachment, wellbeing and mindfulness. Participants (N = 165) completed an online survey which included the Experiences in Close Relationships-Revised Questionnaire (ECR-R), the Friedberg Mindfulness Inventory (FMI-14) and the Depression Anxiety Stress Scale-short form (DASS-21). Results indicated that wellbeing, assessed by measures of depression, anxiety and stress, was strongly associated with an individual's attachment style. However, only attachment anxiety showed a predictive capacity on wellbeing. Furthermore, the results indicate that mindfulness is a significant moderator in the relationship, with mindfulness diminishing the effect of insecure attachment on wellbeing. � 2016 Elsevier Ltd.