Abstract We explore the relevance of procedural justice theory for understanding the relationship between police and marginalized groups and individuals. Analysis is based on ethnographic research into the policing of the street population in an inner London borough through shadowing policing patrols and embedding observation within the homeless community. Police–street population relationships appear characterized by: (1) a structural context of extreme disempowerment; (2) a micro-sociological dimension relating to the exercise of authority and (3) a dynamic power relationship characterized by ‘the game of cat and mouse’. The nature of interactions within this context and the extreme marginality of the street population alter the weight placed on fairness perceptions and the extent to which police activity can affect legitimacy and compliance.