In 2005 Khan, signed for Worcestershire County Cricket Club in England as one of their two overseas players, replacing Shoaib Akhtar. Although Worcestershire went on to lose the match, Zaheer took ten wickets against Somerset on debut; in doing so he became the first Worcestershire player to take 10 wickets on debut for over 100 years. In June he took the first nine wickets to fall in the first innings against Essex, ending with 9–138; had wicket-keeper Steven Davies not dropped a catch offered by last man Darren Gough he would have become the first bowler ever to take all ten for the county.