"We are reluctant to call on the king to reverse a judicial decision, but time and again we have seen Bahraini courts uphold politically motivated charges against those who peacefully dissent," said Joe Stork, deputy Middle East director at the New-York based rights watchdog.
"The courts have failed to uphold Bahrain’s obligation to protect free expression and peaceful assembly," he said in a statement released by HRW.
The HRW statement refers to nine Bahraini doctors and nurses whose convictions were upheld by the kingdom's highest court on October 1.
Six medics were jailed a day later, including consultant orthopaedic surgeon Ali Alekri, who was sentenced to five years, and senior nurse, Ibrahim Damastani, who received three years.
Both men were convicted of possessing a non-firearm weapon and of illegal assembly.
Only five of the medics are currently in jail: one was released Sunday for time served and the remaining three medics had already finished serving their prison terms by the time the high court issued its verdict.
The medics worked at the Salmaniya Medical Complex in Manama during the predominantly Shiite uprising against the kingdom's ruling Sunni dynasty in February of last year.
The public prosecutor's office has charged seven policemen with torture and maltreatment of the medics, all of whom are Shiites, in line with the king's pledge to implement reforms recommended after the brutal government crackdown on the month-long uprising.
Human Rights Watch and several other prominent international rights groups have, however, argued that the kingdom has been slow to implement change.
"The Bahrain government repeatedly claims to have carried out reforms while it violates the most basic human rights of its citizens," Stork said.
"This ... court ruling shows that little has changed when it comes to administering justice."
Sporadic protests continue to this day in Bahrain's mainly Shiite neighbourhoods, often spiralling into violent clashes with police.
According to the International Federation for Human Rights (FIDH), a total of 80 people have been killed in Bahrain since the start of the violence on February 14, 2011.
