This study examined mother-infant attachment relationships as identified by a social work team working with a highly vulnerable cohort. Infants in the ultra-high risk population are most at risk of poor attachment styles. Mothers often have a history of childhood abuse and adversity, criminality, substance abuse, and poor mental health. When combined with socio-environmental aspects within families a high incidence of poor attachment is likely. This study investigated Social Workers’ identification of attachment issues using qualitative methodology in the form of document analysis of Social Worker case notes and semi-structured interviews with Social Workers. Results indicate that the accuracy and frequency of identifying attachment varied and that often the focus was on individual behaviours rather than the dynamic attachment processes of the mother-infant dyad. Disturbance in the attachment relationship was most clearly and accurately identified in cases that involved a major disruption to the mother-infant relationship. Attachment styles were identified as secure in almost every non-crisis case, particularly in the infant’s early years. Possible early manifestations of insecure attachment styles were not viewed through the lens of attachment theory, but rather in the context of behavioural and parenting problems. The potency of the Social Worker-mother relationship emerged as a factor that may in and of itself be crucial in helping mothers attach to their infants.