This report provides information on Mexico's counter-narcotics efforts under the presidency of Ernesto Zedillo from December 1994 to March 1998 in the context of President Clinton's February 26, 1998 certification that Mexico was fully cooperative in drug control efforts. The report focuses on (1) trends in Mexico's share of illicit drug traffic to the U.S., (2) measures of Mexico's efforts to control drug trafficking, and (3) Mexico's cooperation with the U.S. in counter-narcotics efforts.