This thesis is based on an Australian Research Council funded research grant. Fifty-one qualitative interviews were conducted with human service workers to gain an understanding of their interpretations of their clients’ ‘drug problems’ and of their own role, the service system and wider policies. Although harm minimisation has been Australia’s official drug policy since 1985, little is known about how harm minimisation is ‘enacted’ in the helping culture. To date human service workers have not been recognised in their constitutive role in harm minimisation discourse. Whilst a significant part of drug policy interventions are delivered via human services, the helping subject has not come under scrutiny. The drug using subject remains ill-conceived as a result of neglecting its partnering others or indeed its overlapping with other subject positions. Moving beyond recognising workers only in terms of staff opinions and attitudes, a relational and multi-level approach is adopted to introduce more complexity into the debate. After a brief historic discussion of the creation of the ‘human service worker’ and the ‘drug user’ (as client) and methodological considerations about discourse analysis, the thesis proceeds with the introduction of a conceptual framework consisting of four levels: the individual, relational, institutional and cultural political economic level. These levels are used to examine the existing literature on ‘drug problem factories’ and for the analysis of the data. By focusing on these levels the critical analysis of the interview material shows that ‘harm’ and ‘minimising’ are themselves contested categories and that different harms and different harm producing and minimising practices can be identified some of which have come into discourse, others are excluded or entirely absent. The human service workers struggle to make sense of their own role and to define how drug users are being ‘helped’ and could or should be helped. Their understanding of harm minimisation discourse aligns with, supports and/or resists other discourses such as (neo)liberalism, neoconservatism, prohibition and economic rationalism. The workers are portrayed as having substituted increasing complexity for initial simplicity in the course of working with ‘drug users’. In summary, this thesis offers a poststructuralist analysis of how harm minimisation is constituted, negotiated and undermined from the perspective of human service workers and shows how the service systems’ helping cultures enrol human service workers in harm producing and harm minimising practices. Harm minimisation consists of discursive and non-discursive elements and is a product of deliberate social forces as well as messy contingencies and unintended consequences.