Abstract With a strong global demand for some 30 years, natural gas is a particular challenge for countries of South and Central America since each cubic meter of natural gas that is consumed is produced in this continent. It therefore seems appropriate to consider the risk of a collision gas and its effects on the countries most dependent on gas (either as producers or as consumers). Thus, in this paper, we study the vulnerability of gas in several countries on four ratios developed by Cabalu (2010). Once calculated from empirical data, these ratios helped to determine indicators and to classify countries according to their vulnerability in the event of a gas shock (sudden rise in prices). A picture emerges which represents an indicative classification of the countries.