Mukhtar Mai set up two schools in her southern Punjab village with compensation money she received after six members of a tribal council were found guilty of rape and conspiring to rape her in 2002.
The rape was ordered as a punishment for an alleged crime by her brother.
But five of the six men originally sentenced to death had their convictions overturned on March 3, and one had his penalty commuted to life in prison.
The judges cited a lack of evidence. Four of the five were released pending a Supreme Court hearing and the fifth was kept in custody on an unrelated charge.
The men are expected to return to Meerwala, the village where Ms Mai still lives. "I have appealed to the government and judiciary that there is a threat to my life. I am worried about their release. I fear they might kill me," Ms Mai told the AP news agency on Tuesday.
Ms Mai, whose case has become an international cause cel bre, says she has received death threats since she first took her alleged rapists to court and was allocated a 24-hour armed guard by the Punjab government. Since the convictions were overturned, her security detail has been doubled to six men.
In this area of the country, blood feuds over family honour are common and often last generations.
In spite of the risk, Ms Mai refuses to stop running the village's first-ever schools, which she believes are the key to improving life for the next generation of girls. "I won't leave Pakistan or my village. I will continue my work in the schools and increase awareness (of women's rights) as my mission," she said at a press conference in the capital Islamabad.
Ms Mai had called on the government to use preventative detention laws to keep her alleged attackers in prison until she could challenge the decision to set them free. But legal wranglings over which of Pakistan's different courts had jurisdiction over the case meant the issue of their guilt or sentencing were not resolved before they were released on bail.
The original trial took place at an extraordinary session of an anti-terrorism court. But the death sentences handed down by this judge were later thrown out by the province's highest conventional legal authority, the Lahore High Court. Then the Federal Sharia Court, the highest Islamic tribunal in the country, on Friday claimed jurisdiction over rape cases and re-instated the original sentences.
The government has said a hearing by Pakistan's Supreme Court will make a final decision, but a date has not yet been set.