In temperate and oceanic regions, grazed grass is the lowest cost feed available for milk production. In other regions, grazed grass is less important but can contribute to the diet of livestock. Within high output systems the interaction between the animal and sward is challenging for a host of reasons, including intake and milk production potential, substitution, grass allowance, quality, etc., which often means that grass utilisation and quality are compromised. Adaptation of grazing management and implementation of a range of grazing strategies can provide possibilities to increase the proportion of grazed grass in the diet of dairy cows in high output systems. As Europe transitions to a non-milk quota situation, increasing scale, or herd size, will probably lead to a trend towards a reduction in grazing, and may lead to a loss of the benefits of grazing. Therefore, strategies are required to increase the level of grazed grass in the diet of dairy cows on high output farms through the integration of grassland measurement and budgeting within everyday grassland management practices. There is a growing body of literature describing the benefits of grazing from an economic, environmental, animal welfare and overall social dimension. However, there are fewer reviews highlighting the constraints and difficulties to maintaining a high level of grass utilisation and good grazing performance in high output systems. The objective of this review is to present a balanced overview of the possibilities and the constraints for grazing in dairy systems in the future.