A draft constitution under review by the Tunisian National Constituent Assembly is the third presented since the Jasmine Revolution in December 2010. Human Rights Watch said there were worrisome sections in the document.
Tunisia's revolution was the first in a line of upheavals that brought an end to long-standing dictatorships in the region.
Deputy Director of Middle East programs for Human Rights Watch Eric Goldstein said there are considerable improvements over previous drafts, though certain obligations remained excluded from the latest revision.
"The (assembly) should close loopholes in the draft constitution that would allow a future government to crush dissent or limit the basic rights that Tunisians fought hard for," he said in a statement.
The rights organization said there were some provisions that recognized universal human rights apply in the country only if they meet the "cultural specificities of the Tunisia people." The organization said other measures could give Tunisian authorities the means to reduce the significance to certain fundamental human rights.