2012 World Junior Championships in Athletics – Men's 400 metres hurdles

The men's 400 metres hurdles at the 2012 World Junior Championships in Athletics was held at the Estadi Olímpic Lluís Companys on 11–13 July. == Medalists == == Records == Prior to the competition, the existing world junior and championship records were as follows. == Results == === Heats === Qualification: first 3 of each heat (Q) plus the 3 fastest times (q) qualified === Semi-final === Qualification: The first 2 of each heat (Q) and the 2 fastest times (q) qualified === Final === == Participation == According to an unofficial count, 52 athletes from 36 countries participated in the event. == References == == External links == WJC12 400 metres hurdles schedule