Several Bahraini doctors and nurses were sentenced to prison for spreading "stories and lies" and for trying to topple the regime during the country's failed uprising early this year.
All of those convicted had worked at the Salmaniya medical complex in Manama, which was raided by Bahraini security forces in March as part of the regime's crackdown against the Shiite majority.
Bahrain later said it was transferring the cases to civilian courts, though Human Rights Watch said the court should reverse the convictions after finding evidence the suspects were tortured in detention.
"The appeals court should decisively overturn the unfair verdicts against the medics and dismiss outright all politically motivated charges," Joe Stork, deputy Middle East director at Human Rights Watch, said in a statement.
Washington announced last week that a $53 million arms agreement with Bahrain was on hold while it waits for a report from an independent commission monitoring the human rights situation in Bahrain.
Bahrain was criticized for its harsh response to a crackdown against a Shiite uprising this year. The United Nations said many of the country's hospitals were used as torture chambers.