This paper considers the relationship between farm size and productivity patterns across countries and within countries. Across countries, there is a weak but positive relationship between farm size and yield. A much stronger positive relationship holds for agricultural output per unit of labour, which is closely correlated with farm size across countries. The inverse farm size-productivity relationship holds true within countries. However, even within countries, there is typically a strong positive relationship between farm size and labour productivity. Considering that hundreds of millions of poor people will remain in smallholder agriculture for decades to come, policy-makers need to consider whether current strategies offer a particularly valuable way to generate agricultural development.