Christian Louboutin is suing Yves Saint Laurent in a New York federal court.
The lawsuit says Laurent shoes are copying the trademark red soles of Louboutin.
The red soles are often spotted on red carpets, worn by celebs like Sarah Jessica Parker, Scarlett Johansson and Halle Berry.
The suit claims Louboutin came up with the red sole idea, when he painted nail polish on the black soles of a pair of women's shoes.
