In 2004, having finished 2nd at the Kenyan Olympic trials, the young Kipruto won the silver medal in the 3000 m steeplechase at the 2004 Olympic Games. In the 2005 World Championships in Helsinki he won a bronze medal in the same event. He finished third again at the 2005 IAAF World Athletics Final. In 2006 he finished sixth at the World Athletics Final, repeating his place from 2004.