--- - |2+ Abstract Background Individuals with a history of childhood maltreatment are particularly vulnerable to a longer course of depression. Immunisation theories of resilience suggest that resilience and related factors may buffer against the deleterious effects of early childhood adversity. Trait mindfulness is linked to resilience and may be a pathway to cultivating this dynamic process. In this study, we investigated whether trait mindfulness can buffer against the effects of early childhood maltreatment in predicting lifetime number of months depressed. Methods We recruited 43 previously depressed, currently remitted patients, and retrospectively examined their depression history (using a structured interview, LIFE‐SCID (Longitudinal Interval Follow‐Up Evaluation—Structured Clinical Interview for the Diagnostic and Statistical Manual‐IV)), their self‐reported experience of maltreatment in the first 16 years of life (MOPS (Measure of Parental Style)), and their levels of trait mindfulness (MAAS (Mindfulness Attention Awareness Scale)). Results We found that number of months depressed in a lifetime was positively associated with reported childhood maltreatment, and negatively associated with trait mindfulness. Second, we found evidence that trait mindfulness significantly moderated the relationship of early childhood maltreatment and number of months depressed. Specifically, it appears that individuals who report severe histories of maltreatment are especially vulnerable to recurrent depression if they are also reporting low levels of trait mindfulness. Conclusions Increasing mindfulness may be warranted among individuals reporting a history of childhood abuse with lower baselines of trait mindfulness; however, results of this retrospective study require replication in a larger, prospective trial. - Clinical Psychologist, EarlyView.