The first assessments of the Millennium Development Goals of the United Nations have been completed, and deliberations about world health are increasing. Now is an appropriate time to consider the case of Cuba, which has functioned under difficult conditions for many years, and followed its own path. Cuba's health indicators are much better than might be expected considering its level of income; in many cases the indicators compare to those of industrialized countries. These results should be viewed as the product of a well-defined strategy and the use of essential public health principles rather than as the accumulation of better numbers. The Cuban experience demonstrates that a population's health can improve in even the most adverse economic conditions. This is attainable when sound public health practices are implemented under the principle that health is a basic right and therefore a national priority. An understanding of the Cuban public health system can help other low-income countries adapt these practices to their own conditions and meet the Millennium Development Goals. If this were to occur, there would be substantial improvement in the world's health.