© 2020 British Nutrition Foundation Plant-based dietary patterns are associated with reduced risk of many chronic diseases. Athletes have increasingly been adopting plant-based diets not only for the related health benefits but for perceived improvements in endurance performance. Several theoretical mechanistic underpinnings have been described as to why a plant-based dietary pattern may improve endurance performance. This review focuses on plant-based dietary patterns and their hypothesised ability to modulate endurance performance specifically from an antioxidant, inflammatory and immunological perspective. Studies quantifying the function of plant-based dietary patterns on endurance performance are scarce; however, research exploring physiological changes in immune, oxidative and inflammatory systems with the adoption of a plant-based dietary pattern appears to be favourable. Overall, research suggests that the consumption of a plant-based diet may result in improvements in C-reactive protein, interleukin-6, fibrinogen and leukocyte concentrations, while some studies report improved lymphocyte responsiveness and improved natural killer cell functionality. These changes may be the result of an optimised intake of phytochemicals (particularly polyphenols), unrefined carbohydrates and saturated fat which could theoretically translate into small improvements to endurance performance. It is important to note that any improvement to endurance performance via these systems would likely be minor and difficult to quantify; nevertheless, the findings of the current body of evidence highlight the need for further research in this area.