There is a high incidence of medication errors across the NHS that results in significant harm to patients. There is also a lack of literature that explores the incidence and effect of medication errors in specialist cancer settings. However, the underlying factors that contribute to medication errors are universal across all settings. This article explores the risk factors relating to medicines administration in cancer settings – in particular systemic anti-cancer therapy and opioids – and the multifactorial causes of medication errors at the prescription, dispensing and administration stages. The authors suggest steps that can be taken to reduce the risk of medication errors and consider the role of education and non-medical prescribing.