Pharmaceutical prescriptions are quite different in four European countries: Italy, France, Germany, and the United Kingdom. In particular, in 1992, among the 50 most sold products by value, only seven active principles are common to these four countries. In Italy, in 1994, there has been a substantial change in pharmaceutical prescriptions, since, for the first time, drugs have been reimbursed by the National Health System (NHS) on the basis of efficacy. As a result of this new policy, the 50 most-sold products by value have changed dramatically in the first five months of 1994. The pharmacologic and economic implications of this change are discussed.