The London-based human rights group says the three men sent to prison in Laos after helping foreign journalists did not get a fair trial.
Amnesty International is appealing to Vientiane for new trials for Thao Moua, Pa Fue Khang, and Char Yang, who it says were tortured in police custody and were tried without proper legal representation.
The men were arrested in June, along with two European journalists and their Lao-American guide/interpreter, who were reporting on the conflict between Hmong rebels and the Lao government.
Amnesty International is also calling attention to the plight of the Hmong rebels, saying they face starvation and exhaustion following repeated raids by the Lao goverment. At the same time, it calls for all ethnic Hmong groups to stop targeting Lao civilians and to respect the Geneva Convention.