Hundreds of right-wing extremists were pelted with bottles, eggs and firecrackers as they marched through Stockholm.
Three people were injured and at least six people arrested as riot police tried to keep angry counter-demonstrators away from the procession, police in the Swedish capital said.
Parts of the downtown area were sealed off during the protests, which coincided with the annual Nobel Prize ceremony.
Ultra-nationalist groups opposed to immigration have staged similar marches in previous years in a Stockholm suburb where a skinhead was killed 10 years ago.
Police said about 400 people participated in the march, and about as many counter-protesters, including far-left activists, turned up in an effort to stop it.
Two people in the far-right demonstration were taken to hospital after being hit by objects thrown at them, while a counter-demonstrator was hurt when a police van accidentally ran over her foot.
None of the injuries was believed to be serious.