A review of recent quantitative studies on the International Monetary Fund reveals that much of the conventional wisdom is incorrect. Recent studies have demonstrated a new degree of methodological rigor, have drawn more heavily upon insights from political science, and have asked a number of new questions. We review studies of participation in IMF programs, design of IMF conditionality, implementation and enforcement of IMF conditions, conventional program effects and catalytic effects. At every stage, we find substantial evidence of the influence of major IMF shareholders, of the Fund’s own organizational imperatives, and of domestic politics within borrowing countries. We conclude that very little is known with certainty about the effects of IMF lending, but that a great deal has been learned about the mechanics of IMF programs that will have to be taken into account in order to obtain unbiased estimates of those effects.