Attachment theory is familiar to probation workers, with its broad messages that early care can leave a lasting legacy, and that patterns of relating can be repeated throughout the lifespan. Up close however, attachment theory is complex, and research findings sometimes vague or contested. This empirical research examined the use of four key attachment-based concepts in generic probation practice over a period of six months. The concept of the probation officer as a potential secure base was a useful one, as was the idea that service users' early attachment history could help to understand relationships and offending. Other concepts (the reflective function and attachment style) were less useful.