Tunisia's inheritance law is based on Islamic jurisprudence stipulating that men inherit double the amount received by women.
The demonstrators marched to the seat of parliament in the Tunisian capital chanting equal inheritance rights "are a right, not a favour".
Last year, President Beji Caid Essebsi announced plans to set up a commission to examine "individual liberties" and "equality in all domains", including inheritance.
His announcement sparked opposition from Muslim clerics who issued a statement saying the proposals amounted to "a flagrant violation" of Islamic precepts.
Tunisia, which adopted a 1956 Personal Status Code extending several rights to women and abolishing polygamy, is seen as a pioneer on women's emancipation in the Arab world, although tensions often surface between conservatives and reformists.
The 2011 revolution in Tunisia toppled the regime of autocratic president Zine El Abidine Ben Ali and sparked uprisings across the Arab world, where changes to inheritance rights are considered a taboo.
But activists on Saturday stressed the demand for equality among the sexes in Tunisia.
"There must be equality, it is in the constitution," adopted after the 2011 uprising, said Sana Ben Achour, president of the Beity association which supports women.