Atrial fibrillation is one of the commonest arrhythmias. It was first recognized over 100 years ago. However, many aspects including its mechanism, the role of autonomic as well as structural influences, and appropriate management including prevention of embolic events and indications for cardioversion have continued to provide questions for clinicians. This article is not intended to be all-embracing but to deal with some of these more perplexing and controversial areas.