The federation said eight men and three women had tested positive for the banned substance methandienon.
The weightlifters were tested during a training camp earlier this month while preparing for the Games in August.
"The federation decided to withdraw the weightlifting team - men and women -from the Olympics," read a statement.
Bulgaria had been keen to clean up weightlifting's tarnished reputation in the build-up to Beijing after a series of doping scandals.
Olympics 2008 blog
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5 Live's Gordon Farquhar The team was stripped of three gold medals and sent home following positive drugs tests at the Sydney Games in 2000. Among the lifters who tested positive this time are Ivan Stoitsov, who won two gold medals at last year's world championships, and Olympic bronze medallist Velichko Cholakov. "At the doorstep of the Beijing Games our hopes have been damaged," the federation added. "The work has become meaningless and the tears that were to be shed in front of the national flag are replaced by tears of helplessness." The sport has been hit hard by problems with doping in recent years. At the last Olympics in Athens 12 of the 26 positive drug tests came in weightlifting, while earlier this month the International Weightlifting Federation handed out two-year suspensions to 11 Greek lifters who tested positive in March.