Blood transfusion is a relatively common procedure, and is a necessary skill for many nurses working in a range of clinical environments. Blood transfusion carries a degree of risk, and avoidable mistakes can result in serious or fatal consequences. Adverse events are largely associated with human error, so know-ledge and skills are essential. While local and national policies go some way to reducing clinical risk, a comprehensive knowledge of the blood grouping system and compatibility, and the ability to recognise, respond to and report reactions, are also necessary to optimise patient safety. An online Nursing Times Learning unit on safe blood transfusion will be launched next month.