"All the hostages have been freed" at the Viana prison, said the spokesman for the state justice secretariat of Espiritu Santo state.
Rioting prisoners seized members of visiting families on Saturday as a protest against conditions in the jail.
The spokesman insisted that the prisoners "got nothing" from the state to end the uprising, despite demanding the return of five inmates transferred to a federal penitentiary a month earlier.
Two prisoners have been killed, one of them decapitated, over the weekend with the bodies of the victims displayed on a wall outside the prison walls.
The rioters are armed with five pistols and two grenades and want to negotiate an end to their mutiny in the presence of representatives from the Catholic Church.
Local state officials had asked the central government to deploy of 300 soldiers to help crush the riot. The inmates have complained about food and about transfers of some inmates to other prisons.
The uprising came nearly a month after some 170 people were killed, including scores of police, in a coordinated rebellion by a prison-based gang in Sao Paulo state just south of Espirito Santo.
The gang unleashed a bloody street offensive, attacking police in retaliation over the transfer of some gang leaders to remote prisons.
The Catholic Church says a prison mutiny occurs every 36 hours in Brazil amid overcrowding in the country's jails.
According to a government study published in July 2004, the number of prisoners has doubled over the past eight years in Brazil.