The increasing emphasis on the drug–crime link in British drug policy in recent years has had a knock-on effect on British drugs research. Research is now taking place more and more within the criminal justice system, rather than exclusively in the traditional sites of the community or drug treatment services. This shift has posed some significant challenges for drugs researchers but these have been little discussed to date. This article aims to address this gap by critically reflecting on the recent experiences of a team of researchers engaged in a drugs research study that involved interviewing arrestees in police custody suites. Key issues raised include gaining access to research sites, establishing a clear research identity, and ethical concerns. Some recommendations for research practice are made.