2004 World Junior Championships in Athletics – Women's 400 metres  The women's 400 metres event at the 2004 World Junior Championships in Athletics was held in Grosseto, Italy, at Stadio Olimpico Carlo Zecchini on 13, 14 and 15 July.  15 July 14 July 13 July According to an unofficial count, 29 athletes from 24 countries participated in the event.