Nash, who joined Yahoo in January 2007 as its PR head, will assist in the transition once her replacement is found, said Brad Williams, a company spokesman, noting she is not leaving to take another job.
Nash's resignation announcement comes less than three weeks after Yahoo named its new CEO Carol Bartz.
Her pending departure follows that of Yahoo president Sue Decker, who announced in mid-January plans to resign after she was passed over for the CEO post.
Nash, however, did not have her hat in the ring for the CEO job and it's not clear what her future plans will entail. Nash was not immediately available for comment.
The departure of Yahoo's PR head was first reported in AllThingsD.