Nusrat, 82, had been living in Dubai since the time Benazir Bhutto went into self-exile in the 1990s. She was reportedly suffering from Alzheimer's disease and was largely incapacitated.
The daughter of a wealthy Iranian businessman, Nusrat was born in Esfahan on March 23, 1929. Her family later moved to the Pakistani port city of Karachi. She married Zulfiqar Ali Bhutto in 1951, becoming his second wife.
After Zulfiqar Ali Bhutto was executed during the regime of military ruler Zia-ul-Haq in 1979, Nusrat became the leader of the Pakistan People's Party and played a key role in grooming Benazir for taking over the party.
Though she left Pakistan in 1982 to seek treatment for cancer in Britain, she subsequently returned to the country and was elected to the parliament from Larkana, the Bhutto family's stronghold in Sindh province. She served as a federal minister in the governments headed by her daughter Benazir.
Nusrat was rarely seen in public over the past few years, including after Benazir's return to Pakistan from self-exile in late 2007.
Following Benazir's assassination the same year, her widower President Asif Ali Zardari visited Nusrat in Dubai several times.
Media reports said Nusrat's body would be flown from Dubai to Larkana in a special aircraft later in the day.