1988 World Junior Championships in Athletics – Men's 400 metres

The men's 400 metres event at the 1988 World Junior Championships in Athletics was held in Sudbury, Ontario, Canada, at Laurentian University Stadium on 27, 28 and 29 July.

Final
29 July

Semifinals
28 July

Heats
27 July

Participation
According to an unofficial count, 46 athletes from 33 countries participated in the event. • 🇦🇬 antigua and barbuda (1)

• 🇦🇷 argentina (1)

• 🇦🇺 australia (2)

• 🇧🇷 brazil (2)

• undefined (1)

• 🇧🇬 bulgaria (1)

• 🇨🇦 canada (2)

• undefined (1)

• 🇨🇺 cuba (1)

• 🇪🇨 ecuador (1)

• 🇪🇹 ethiopia (2)

• 🇫🇷 france (2)

• undefined (1)

• undefined (1)

• 🇮🇹 italy (2)

• 🇯🇲 jamaica (2)

• 🇯🇵 japan (2)

• 🇰🇪 kenya (2)

• undefined (1)

• 🇳🇿 new zealand (1)

• undefined (2)

• 🇵🇰 pakistan (1)

• 🇵🇱 poland (2)

• undefined (1)

• undefined (1)

• undefined (1)

• 🇸🇴 somalia (1)

• 🇪🇸 spain (1)

• 🇺🇬 uganda (1)

• undefined (2)

• 🇺🇸 united states (2)

• undefined (1)

• undefined (1)