Since the identification of phosphorus as a major pollutant of fresh water systems, much research has been done on mitigation options such as agricultural best management practices. Regulatory agencies in the US and other countries have now driven the implementation of many of these mitigation options to protect water quality. However, there is great variability between watersheds, states and countries in the mitigation options selected, due to differences such as predominant type of agriculture, climate and politics. Sometimes specific practices are mandated, such as nutrient management plans, manure application setbacks or the use of feed manipulation to decrease manure nutrient concentrations. However, farmers often have flexibility to choose from a suite of management practices to decrease phosphorus losses, such as when a Phosphorus Index is used. To maximize the benefits to water quality, while minimizing costs and inconvenience to farmers and tax payers who often subsidize implementation, it is essential that the most appropriate management options are used in each situation. We will give examples of how mitigation options have been adopted in the US and Europe, and evaluate how successful they have been towards achieving their aims of improving water quality.