The six were involved in the death of 23-year-old Latifa Hachmi from Schaarbeek (Greater Brussels) in 2004.
Ms Hachmi died at home on 5 August 2004 after suffering sustained violence as part of an Islamic exorcism.
The six people convicted made the woman drink large quantities of water, hit her and forced her under water.
The jury decided that these were conscious acts of torture and ruled that four of the six were guilty of torture leading to the death of Ms Hachmi.
The four are a Belgian convert to Islam, two women of foreign descent and Ms Hachmi’s husband.
The chief exorcist and one of his assistants were not present during the final few days of Ms Hachmi’s live and were consequently only found guilty of torture.
The victim’s brother told journalists that he is satisfied with the verdict. However, counsel for the exorcist says that his client maintains that what happened to Ms Hachmi did not constitute torture.
The four convicted of the more serious offence risk between 20 and 30 years in prison, while the two others risk sentences of between 10 and 15 years.
However, as the six people convicted were not detained, it is feared that they may go on the run before sentence is past next Monday.