In a country where strong personalities are slain for speaking out against the religious-right, Edhi had no compunctions about criticizing radical Islamic and its preachers, and he didn't give two hoots about those who dubbed him an infidel and branded his work as "un-Islamic".
His son Faisal Edhi said Edhi had been admitted to the Sindh Institute of Urology and Transplantation on early Friday and put on life support.
Faisal said Edhi's kidneys failed in 2013 and he was on dialysis but he couldn't get a transplant because of his frail health.
Rehmatullah Mosa Ghazi, Charge d'Affaires at the Afghanistan Embassy (R), greets Abdul Sattar Edhi, Pakistan social worker, at the Afghan embassy in Islamabad, Pakistan, March 27, 2002.
His son, Faisal Edhi, confirmed the news of his death.
"While heading one of the largest private social service in the world, Mr Edhi lived a very humble life with negligible possession and wore his greatness lightly".
Soon after the news of his death last night, hundreds of people gathered outside the hospital.
Edhi migrated to Pakistan in 1947 and made a living at first by working as a commission agent selling cloth at the Karachi wholesale market.
The philanthropist, who was known as the "angel of mercy" or Maulana Edhi, had kidney and sugar-related issues and was in hospital for several weeks for treatment.
Social media quickly lit up in honour of the man whose work uplifting the nation's destitute and orphans cemented his place in the hearts of Pakistan's masses.
Edhi never finished school but later said that the world of suffering became his tutor. "Our graves will benefit the mentally disturbed, we shall stand guardian over them forever", he wrote in autobiography 'A Mirror to The Blind". Motivated by a spiritual quest for justice, Edhi and his team created maternity wards, morg-ues, orphanages, shelters, and homes for the elderly, picking up where limited government-run services fell short. With his wife, Bilquis, Edhi went on to fill the void in public services for society's worst off left behind by a state struggling to contend with Karachi's rapid growth.