The Gender and Equal Opportunity Bill was thrown out on Tuesday after several lawmakers opposed it on religious grounds.
Some quoted the Bible while others said the bill defied sharia, which is recognised by the constitution in Nigeria - home to the world's largest equal mix of Christians and Muslims.
Activists said the dismissal of the bill demonstrated that the government was ignoring the dangers facing Nigerian women, ranging from sexual assault and abduction to forced marriages.
"Nigeria's Senators showed they simply do not grasp the degrading and discriminatory treatment that many of this country's women face on a daily basis," said Mausi Segun, Nigeria Researcher at Human Rights Watch.
The opposition to the bill for religious and cultural reasons not only denies women their rights, but reinforces attitudes that fuel abuse and discrimination, Segun added.
The bill set out equality for women in marriage and divorce and inheritance rights for girls and widows - stating that they should not face "inhuman, humiliating or degrading treatment".
The rejected bill also called for women to be able to participate in politics without any restrictions or barriers - in a country where only seven of the 109 senators are women.
Action Aid's country director Ojobo Ode Atuluku lamented the "chauvinistic utterances" of some of the male senators.
"Parliamentarians to whom women extended massive electoral support are already reneging from their campaign promises to lift girls and women out of violence and discrimination," said Saudatu Mahdi of the Abuja-based Women's Rights Advancement and Protection Alternative.
Several activists questioned why Nigeria had ratified the Maputo Protocol, an international treaty on women's rights, and the African Union Women's Rights Framework, if the country was not prepared to enshrine women's rights at a national level.
"We truly still have a long way to go," said Nigerian human rights activist Bukky Shonibare.