Under the bill, it would be legal to have 25 milligrams of heroin, a fifth of an ounce of marijuana or half a gram of cocaine. The bill also makes it legal to possess small amounts of LSD, hallucinogenic mushrooms, amphetamines and peyote.
President Vicente Fox had proposed the law in January 2004 in the hopes of slowing down the rapid growth in drug addiction and the ranks of small-time dealers that has hit Mexican cities and towns in recent years, just as it has long plagued American cities.
Both houses of the Mexican Congress passed it in a last-minute flurry of legislation as their session drew to a close. The final version of the bill passed the Senate by a vote of 53 to 26 during an all-night session that ended Friday morning. After its final approval, the president's spokesman, Ruben Aguilar, said Mr. Fox would sign it into law.
U.S. reactions: Unnamed U.S. diplomat calls the move unhelpful, and impressively named State Department spokeswoman Janelle Hironimus babbles boilerplate. San Diego mayor Jerry Sanders says it's "just plain dumb." Los Angeles NORML director Bruce Margolin says the quantities are too small.
Thanks to Ryan Posly and Dan Playstead.