Gas hydrates occur in many places around the world and have brought great interest to the international scientific community. They constitute a new exploratory frontier of a promising energy source for the coming century. In spite of that, little is known about their natural environment in subsurface deposits, due to the high instability of these compounds under STP conditions. Speculative global estimates on total amount of gas hydrates in these deposits converge at around 10000 gigatons of carbon (700,000 TCF of methane gas), correscponding to twice the estimated amount of carbon in all other fossil hydrocarbon deposits on earth. Such estimates do not take into consideration the presence of free gas trapped by the hydrate layer. This work aims to discuss potential occurrences of gas hydrates offshore Brazil, particularly in the Pelotas and Foz do Amazonas basins, located at the extreme portions of the Brazilian continental margin. The Pelotas Basin gas hydrates occur in area of 45,000 km (super 2) , in water depths varying from 500 to 3500 meters, while the limits of occurrences of Foz de Amazonas Basin are being established. The limited amount of data available in these regions does not allow genetic interpretation or quantification of recoverable reserves. However, the evidence for gas hydrates observed on seismic profiles may constitute an important asset for the future, particularly if technological advances in extracting gas from hydrates result in economically viable projects. Based on parameters obtained from ODP (Leg 164 Scientific Prospectus), the Pelotas Basin deposit would have a preliminary volume estimate of methane (on surface) of 782 TCF, of comparable to the largest ones worldwide.