This review includes 26 reporting countries within the subject area--10 of which are established producers of petroleum and collectively account for 15% of total world production. The total production from these countries rose for the sixth successive year and for 1964 averaged 4,183,450 b/d--up 4.3% from 1963. Of this production, 81% comes from Venezuela, and Venezuela continues to be the world's largest exporter of petroleum. Geological and geophysical activity in the search for new reserves totalled 1,418 party-months--up 6% over 1963. More than 75% of this work was done in 3 countries--Argentina, Brazil, and Colombia. In the review area, 328 exploratory wells were drilled, 131 of which were successful. Development drilling continued to decline; there were 2,334 such w lls drilled in 1962, 1,824 in 1963, and 1,652 in 1964. Much of this decline in development drilling was in Argentina. Accompanying the text are 26 map-figures, and 73 tables.