The pair are said to have argued after Nicolette - who plays maneater Edie Britt in the hit series - wanted a designer bag created for Eva's character Gabrielle Solis.
Designer Charlie Lapson, who created the burgundy leather tote, says the fighting got so unbearable her was forced to create a different bag to keep the two actresses happy.
He told Britain's Mail On Sunday newspaper: "Both the girls wanted the bag for this one scene. They argued and argued until I decided to design a new bag for Eva."
The handbag which caused such a fuss was auctioned for charity last week.
Last week, Eva was injured on the set of Desperate Housewives.
The actress was taken to hospital after slipping and bruising her ribs on Thursday.
Her publicist, Liza Anderson, said: "Eva slipped on one of the stairs coming out of her trailer. Nothing is broken, but her ribs are very bruised."
Despite the injuries, the 31-year-old actress was back on set within a matter of hours.
Source: Bang! Showbiz