The 25-tonnes of food, medicine, tents and mattresses was scheduled to depart New Delhi on board an Indian Air Force aircraft during the afternoon on Tuesday.
"It should leave between 1530 (1000 GMT) and 1600. For Islamabad it should be about two hours travel time maximum. It should reach Islamabad evening time," said an air force spokesman.
Foreign Secretary Shyam Saran announced the aid effort on Monday evening as the toll in Pakistan was estimated as high as 40,000 with another 60,000 injured.
Almost 1000 Indian lives were lost in Indian-administered Kashmir.
First of its kind
Saran said that the humanitarian mission was very likely the first such airlift from India to its longtime enemy since the 1971 war between the two countries.
"The prime minister (Manmohan Singh) has directed that a consignment should be put together on an urgent basis and delivered to Pakistan," Saran said.
Pakistan's ambassador to India, Aziz Ahmed Khan, had accepted India's offer after meeting Singh.
Injured survivors are in
desperate need of help
As India and Pakistan grapple with the aftermath of Saturday's earthquake, analysts in both nations said that the aid delivery could spur their peace process.
Uday Bhaksar, deputy head of the Institute of Defence Studies and Analyses, a New Delhi think-tank, called it a "symbolically important" development.
"In the past there has been a certain reluctance by Pakistan to accept assistance from India," Bhaksar said. "This will have a positive effect on the peace process and the perception of one about the other."
The shared tragedy has struck both sides of the de facto border that divides Kashmir, a disputed Himalayan territory that has twice led the two nations to war.
"It is a very good development in bilateral relations between the two countries"
IA Rehman, Human Rights Commission of Pakistan
"It is a very good development in bilateral relations between the two countries," said IA Rehman, head of the independent Human Rights Commission of Pakistan.
"In tragedies like this, when people are afflicted, rivals come to their senses. They realised they need to work together," he said.
India and Pakistan began a peace process in January 2004 that renewed cultural, sports and economic links snapped in 2002.
The two countries had massed troops at their border in 2002 following an attack by suspected Pakistan-backed separatists on India's parliament. India blamed Pakistan for the attack, while Islamabad denied the charge.
They have since been involved in peace talks including confidence-building measures to avoid an accidental nuclear war between them.
But mountainous Kashmir remains at the heart of their dispute.
Kashmir remains central to the
New Delhi repeatedly accuses Pakistan of not reining in Muslim fighters who infiltrate Indian-held Kashmir to wage a bloody separatist war.
"The latest development augurs well in improving relations between Pakistan and India," Pakistani political and defence analyst, retired Lieutentant-General Talat Masood, said.
"It shows both countries want to show goodwill whenever the opportunity arrives," he said. "As Pakistan is in distress, it is a good gesture from India. Pakistan has made similar gestures to India in the past."
In the wake of an earthquake in the Indian state of Gujarat in 2001, Pakistan sent several planes with tents and other relief supplies to India.