General hospital clinicians frequently deal with injecting drug users because substance use has diverse medical and psychiatric complications. Non-specialist clinicians often initiate management when specialist consultation is not available or accepted by the patient. Here, we summarise evidence for the management of hospitalised injecting drug users. The first challenge is to engage a drug user into medical care. A non-judgmental approach towards patients and acceptance of their lifestyle choices facilitates engagement. Pragmatic clinical goals can be negotiated and achieved. We also describe common conditions of injecting drug users. Accurate diagnosis and appropriate management focus on common issues such as intoxication, withdrawal, pain management, drug seeking, psychological comorbidity, behavioural difficulties, and pregnancy. Effective management can reduce the medical and social effect of these conditions and is not difficult.