The growth of street gangs in England has led to widespread public and governmental concern, as well as heightened academic interest (Pitts 2008). However, the extent to which such gangs have penetrated English prisons is a question which remains largely unexplored. This research aims to fill the gap existing in the current body of academic work. Through conducting a semi-ethnographic study of a large local prison in the North of England, this study compares the structuration of English prison gangs with their street counterparts. The study employs a qualitative methodology, principally drawing its conclusions from interviews conducted with prisoners. Using an inductive approach, the study’s findings are placed within the wider body of literature on criminal gangs and delinquent behaviour. The results indicate that a significant number of gangs have been imported from ‘the street’ into the sample-site prison. There is a clear continuation of street gang identities within the prison, leading its administration to acknowledge their existence, and to create strategies which moderate their influence on the prison environment.