Arrhythmias are disturbances in normal cardiac electrical activity. They occur in structurally normal hearts, but are sometimes indications of underlying congenital or acquired abnormalities. Arrhythmia can be a mild or transient problem; however, the potential exists for severe life-threatening pathology - even death. It is important that primary care practitioners can recognise various arrhythmias and understand their management. The GP’s role in arrhythmia care ranges from primary diagnosis, through initiation of treatment or monitoring to long-term management of some conditions e.g. atrial fibrillation. Patients require advice about driving or employment, and occasionally the GP may act as a critical link in the ‘chain of survival’ when responding to a cardiac arrest. This article highlights the key findings that can be identified from history and examination, and how these can guide subsequent investigation and diagnosis. The features of common, major arrhythmias and their immediate and subsequent treatment are discussed.