This thesis explores the subject of homelessness from a psychoanalytic perspective and suggests that the key causal factor in the lives of people who are homeless is trauma in the early environment. The theories of Winnicott, Bowlby and Rogers are critically analysed and compared due to their focus on the significance of the relationship in development and the influence of the external environment. The thesis is divided into four chapters. The first chapter explores the backgrounds and political views of Winnicott, Bowlby and Rogers, their beliefs on the optimal conditions for development, the relationship between the inner psyche and the external environment, and their work with delinquent youths. They contend that every individual has the potential for healthy growth if provided with a nurturing environment and advocate for care of the most vulnerable in society. The second chapter examines the theorists’ beliefs on the nature of trauma in the early environment and the impact of this on an individual’s mental health. They suggest that impingements and compliance are detrimental to development and lead to defensive exclusion, fragmentation and a lack of self agency. The third chapter looks at Winnicott’s, Bowlby’s and Rogers’ beliefs on the nature of the therapeutic relationship. They describe the ways that the therapist should provide a facilitating environment for the patient to enable them to establish an integrated sense of self. The fourth chapter considers the main themes in my therapeutic work with individuals who are homeless and whether the concepts of Winnicott, Bowlby and Rogers can be beneficially applied to this practical context. This thesis proposes that Rogers’ core conditions are crucial to therapeutic work with people who are homeless, but in conjunction with psychoanalytic developmental theories to understand primitive defense strategies and contain transferential enactments. The contribution of this research in the field of psychoanalysis includes the consideration of the traumatic roots of homelessness and the application of Winnicott’s, Bowlby’s and Rogers’ theories to therapeutic work with people who are homeless