This paper presents series on top shares of income and wealth in Spain over the 20th century using personal income and wealth tax return statistics. Top income shares are highest in the 1930s, fall sharply during the first two decades of the Franco dictatorship, and have increased slightly since the 1960s, and especially since the mid-1990s. The top 0.01% income share in Spain estimated from income tax data is comparable to estimates for the United States and France over the period 1933-1971. Those findings, along with a careful analysis of all published tax statistics, suggest that income tax evasion and avoidance among top income earners in Spain before 1980 was much less prevalent than previously thought. Wealth concentration has been ab...