This paper puts the recent evolution of tax revenues in developing countries in historical perspective. Using a novel dataset on total and trade tax revenues we compare the fiscal cost of trade liberalization in developing countries and in today's rich countries at earlier stages of development. We find that trade liberalization episodes led to larger and longer-lived decreases in total tax revenues in developing countries since the 1970s than in rich countries in the 19th and early 20th centuries. The fall in total tax revenues lasts more than ten years in half the developing countries in our sample.