The article addresses the question to what extent American antitrust policy in Germany and Italy during the 1950s, was a success or not. Did these nations adopt this policy, did they adapt themselves to it, or did they completely reject it? By a detailed comparison of these two big European nations, Germany and Italy—both defeated powers of the Second World War, and both therefore strongly dependent on postwar American aid—the effects of the American antitrust policy will be analyzed. Eventually, the Germans better adapted, after initial resistance of German big business, to the American plans than the Italians, however, only in an amended and softer form. The Italian resistance—but we even use the expression prolonged rejection—to the economic reforms were much stronger. The US administration envisioned a unified free European market without cartels as early as 1943, however, it would take another fifty years before these ideas would be implemented.