Early-life experiences profoundly impact people's physical and mental health across the lifespan. According to various theoretical models, this impact is most salient when confronted with stressful life experiences. Attachment theory provides a theoretical framework to understand individual differences in adult health related to how early-life experiences shape individuals’ perceptions of the self and others. Based on the need for further empirical investigation into early-life experiences and health in bereavement and related calls for a lifespan approach in psychology, this study examined the influence of early-life experiences with one's primary caregivers as a vulnerability (or diathesis) for poorer health in older adulthood generally, and in the context of spousal bereavement. A sample of 103 participants were interviewed about their childhood experiences with primary caregivers (using Adult Attachment Interviews, a well-established semi-structured interview technique) and were assessed based on depressive symptoms, grief symptoms (for bereaved participants only), self-rated health, and inflammation. There was no evidence in this sample that having a secure state of mind regarding attachment promoted better physical or psychological health; instead, there was preliminary evidence that an insecure attachment state of mind, specifically a dismissing attachment state of mind, was associated with better self-rated physical and emotional health and lower levels of IL-6sR. These findings provide novel insights into attachment system functioning and psychological and physical health in adulthood.