The 4,605 children between the ages of six and 14 dressed in traditional white dhotis - long loin cloths - came dressed in spectacles, fake moustaches and skull caps and carried bamboo sticks.
They assembled for four hours at Bangalore's Kanteerva Stadium for Guinness adjudicators to count and verify the numbers.
The record had been previously held by a school in the neighbouring state of Tamil Nadu.
Gandhi, popularly known as Mahatma (Great Soul), was India's greatest leader who fought for the country's independence from British rule and for the rights of the poor.
School children in the southern Indian city of Bangalore have created a world record for "the largest gathering of people dressed as Mohandas Gandhi".