The supermarket giant has defended selling white My Lovely Baby at £5.96 - but the black My Beautiful Baby at only £4.97 – in its store in Dudley, West Midlands.
The discrepancy led to one angry mum slamming the decision as 'disgusting'.
Holly Beckett, 22, went to the branch to buy a toy for a pal's hospitalised daughter.
But when she saw two Emmi Baby Dolls for sale side by side she was amazed to see the white version was more EXPENSIVE than the black.
Holly - a former Tesco employee who shops at the giant store - told the Sun: "I think it's disgusting I have to pay one pound more because it's a white baby.
"At first I reported the price difference because I was worried about what people would think about Tesco.
"As an ex-employee I didn't want them to get involved in some kind of race row."
Holly said she and other customers thought the reason for the price variation was because the dolls have a 'different ethnicity'.
Despite having different names the dolls are the same apart from different coloured skin and outfits - one pink, one purple - and they make different sounds.
Pictures on the side of their boxes display a black girl playing with the black doll and a white girl playing with the white one.
Holly reported the price difference to staff but said she was told it was a simple 'pricing error'.
But when she returned to the store a week later there was still a price difference. Holly said when she complained to store staff they tried to offer her the white doll at the SAME price as the black one.
She added: "It's not about the money, but the fact is the white doll is a quid more dear than the black one and that can sow all kinds of ideas in people's heads."
A Tesco spokesman said it was because the black dolls went on sale after the white ones - but at the "introductory" price the white ones had originally been sold for.
"At present the product is being sold at an introductory price. That is all there is to it."