Russia's Supreme Court has upheld the verdict in the high-profile killing of a nine-year-old Tajik girl in 2004.
Khursheda's father and nephew were injured in the attack
In March, seven defendants were found guilty of hooliganism and one of them was found not guilty of murder.
Khursheda Sultonova died of 11 knife wounds in St Petersburg after being attacked by a group of teenagers.
The seven teenagers were given jail terms of 18 months to five-and-a-half years. Prosecutors and defence lawyers appealed against the verdict.
The jury also rejected prosecution claims that the attack in February in 2004 was ethnically motivated.
Ethnic minority activists in Russia have raised concerns that the ruling could provoke more attacks by racists who think they can act with impunity.
Russia has recently witnessed a series of attacks targeting foreigners and representatives of ethnic minorities. Some of the attacks were fatal.
"The panel of judges ruled to uphold the verdict delivered by the St Petersburg City Court on 30 May to seven defendants," said the Supreme Court's ruling, quoted by Russia's Itar-Tass news agency.
The court also dismissed requests by both sides to hold a retrial, without further elaboration.
Prosecutors had been pressing for a retrial, arguing that "the jury sympathised" with the defendants, Itar-Tass reported.
The defence lawyers also expressed dissatisfaction with the court's ruling, claiming that the trial was flawed.
They said they did not rule out appealing against the verdict to the European Court of Human Rights.