Kim Kardashian, Khloe Kardashian and Kourtney Kardashian use the Khroma name for a line of make-up and beauty products sold across the US at drug stores and some cosmetic counters.
A Los Angeles boutique owner called Michael Rey is now claiming the Kardashians have hurt his own Chroma Makeup brand by selling their similarly-named products at lower-end stores.
Rey - who founded his Chroma Makeup store over a decade ago - told TMZ that the Kardashian products create confusion for his customers.
He has apparently hired attorneys, but has asked the Kardashians to simply change the name of their beauty line before taking any legal action.
A spokesperson for the Kardashians has not responded to Rey's request.
Khroma Beauty was launched earlier this year, with the sisters saying at the time that their own make-up product line was "a dream come true".