Each year, 15 million people worldwide and 110 000 people in England have a stroke. Having a stroke increases the risk of having another. There are a number of additional known risk factors that can be modified by diet. The present study aimed to systematically review key nutrients and diets and their role in secondary prevention, as well as provide evidence-based guidelines for use in clinical practice. The work was conducted as part of the process to develop the 4th edition of the Royal College of Physicians' (RCP) National Clinical Guideline (NCG) for Stroke.