White teens were the most likely to say they had abused prescription drugs, with 23 percent admitting they had taken a drug such as OxyContin, Percocet, Xanax or Ritalin without a doctor's prescription, the study by the Centers for Disease Control and Prevention (CDC) found.
Seventeen percent of Hispanic teens and 12 percent of blacks said they had abused prescription medications.
The 2009 study, which surveyed 16,000 US high school students, also found that nearly three-quarters of US teens have used alcohol, more than a third -- 37 percent -- have used marijuana, 6.4 percent have used cocaine, nearly seven percent have used ecstasy and four percent have use methamphetamine.
"Some people may falsely believe that prescription drugs are safer than illegal drugs yet their misuse can cause serious adverse health effects, including addiction and death," said Howell Wechsler, director of the CDC's division of adolescent and school health.
The findings come from the National Youth Risk Behavior Survey (YRBS), which has been conducted every other year since 1991.
The question about prescription drug use was asked for the first time last year.