Whilst the concept of ‘race’ has no basis in genetics or biology, the dynamics of racism pervade all aspects of modern life - including the consulting room. In this paper the relationship between a white therapist and a black patient is explored through an unbidden thought and a verbal slip that occurred in the course of the therapy. The amplification and examination of these unwanted ‘slips’ are used to shed light on the subtleties of the effects of difference in colour on the relationship. It is argued here that the interaction reflects and illuminates the asymmetrical relationship between ‘black’ and ‘white’ in modern western society. This is then considered using the concepts of the cultural unconscious and social unconscious as ways of understanding the tenacity of racism in ourselves.