Surgeons in the city of Indore are reported to be 'converting' hundreds of girls a year, who are subsequently pumped full of hormone drugs.
A report in the respected Hindustan Times newspaper said the 'shocking, unprecedented trend, catering to the fetish for a son, is unfolding at conservative Indore's well-known clinics and hospitals on children who are one to five years old.
'The process being used to 'produce' a male child from a female is known as genitoplasty.
Indian society places a strong value on producing a son and heir, with daughters often seen as an expensive burden to be married off.
Sex determination tests during pregnancy are illegal in India to try to prevent the common practice of women choosing to abort female foetuses.
In some states such as Punjab the ratio of women to men has dropped as low as seven to ten.
Wealthy parents from Delhi and Mumbai are reportedly flocking to Indore, a city in the centre of India, for the relatively low cost £2,000 treatment to surgically 'correct' their daughters.