When patients present with red lower legs, the cause is often assumed to be cellulitis or erysipelas. There are, however, several alternative conditions which mimic the clinical signs of cellulitis or erysipelas, which can lead to misdiagnosis. It is important that the cause is correctly diagnosed to prevent inappropriate prescribing of antibiotics. This article discusses the different potential causes of ‘red legs’, in addition to cellulitis and erysipelas, together with clinical signs and symptoms to enable general practice nurses (GPNs) to differentiate between them and implement appropriate treatments