"Kuwait’s authorities should revoke (a law) ... to ban all demonstrations because it denies the right to peaceful assembly," said Joe Stork, deputy Middle East director at New York-based HRW.
"The government has an obligation to respect the right to gather peacefully regardless of whether demonstrators support or oppose its policies."
More than 150 protesters and 24 police have been slightly injured at three demonstrations since October 21 held to protest a decree by the emir to amend the electoral law.
"If force is required to quell violence by protesters it should be the absolute minimum necessary to protect lives and property," Stork said.
"The right to peaceful assembly is enshrined in the constitution Kuwaitis will be celebrating... Authorities should lift the ban and permit people to express their views," he said.
Kuwait's government is marking on Saturday the 50th anniversary of its constitution, with a display of fireworks. The the opposition will celebrated on Sunday with a massive rally.
The opposition has been protesting the amendment to the electoral law they say amounts to a coup against the constitution because it allows the government to influence the outcome of parliamentary elections set for December 1.
It is boycotting the election, and no one from among its ranks has registered to run for office. It has been urging people not to vote.