This paper provides detailed farm level data evidence on the dynamics of farm performance from case studies covering crop farms in Australia, France, Italy and the United Kingdom (England and Wales), and dairy farms in the Czech Republic, Denmark and Norway, with different recent sample periods of five to thirty years. An increase in productivity over time is common to all countries and most crop farm classes, but productivity dynamics vary significantly. In Australia, strong productivity growth among the most productive crop farms has led to an increase in the gap between the highest and lowest performing farms; whereas in France, Italy and the United Kingdom, productivity growth was weak among the most productive crop farms and the lowest performing farms closed the productivity gap. Productivity also increased among dairy farms, with an increasing gap between the most and the least productive farm classes in the three sample countries. The impact of policy changes on performance dynamics is analysed for decoupled payments in France and England, and dairy payments in the Czech Republic. The main findings across countries and policy implications are discussed in OECD Food, Agriculture and Fisheries Paper N°164.