This paper presents the first set of estimates of the rentier share of income for twenty-nine OECD countries. We define rentier share to mean the income accruing to financial institutions and the holders of financial assets. The years of coverage vary by country, but span the period 1960-2000. The paper presents the estimates, describes in detail the methods used to construct the series, and presents comprehensive information on our data sources. In addition, we compare the trends in rentier shares with the share of income going to non-financial corporations. Overall we find that the rentier share of income rose in most countries between the 1960's and 1970's on the one hand, and the 1980's and 1990's, on the other. At the same time, movements in rentier income over this period vary from country to country, and are quite variable over time. We also present estimates for rentier shares including capital gains for a subset of countries in the 1980's and 1990's. Including capital gains substantially alters the trend of rentier shares in the 1990's, in most cases, causing them to increase.