Taurasi, of the Phoenix Mercury, has been playing in Turkey during her league's off-season in the United States.
A news release from the federation said Taurasi tested positive in a routine urine sample for Modafinil, a substance used for sleep disorders.
She was suspended on a "provisional basis" until further testing is completed, the federation said.
Many WNBA women play for European teams during the U.S. off-season.
Taurasi played in Russia the previous four years.
The former University of Connecticut star has led the WNBA in scoring four times and won the league's MVP award in 2009.
Taurasi helped lead the Mercury to the WNBA championship in 2007 and 2009.
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