Bacall became irritated during an interview with Britain's GMTV Wednesday when the younger actress was described as "a legend."
"She's not a legend," Bacall said, cutting off interviewer Jenni Falconer in mid-sentence.
"She's a beginner. What is this 'legend'? She can't be a legend at whatever age she is. She can't be a legend, you have to be older."
The two actresses were in Venice, Italy to promote their new film "Birth," (search) in which 79-year-old Bacall plays Kidman's mother.
At a joint interview, reporters peppered Kidman with questions and, embarrassed, she finally suggested they direct their questions elsewhere.
Bacall, the former wife of Humphrey Bogart (search) and star of such films as "The Big Sleep" and "Key Largo," insisted she and Kidman get along famously.
The two women acted together once before, with Bacall playing a supporting role in Kidman's star vehicle "Dogville" last year.
"I love working with a young actress," Bacall said. "Nicole and I worked together on Dogville and we were friends when we started this. That laid the groundwork for our fabulous relationship on screen and off."
In the film, Kidman plays a woman who believes her dead husband has been reincarnated in the body of a 10-year-old boy.
The assembled stars and the film's director and producer, were asked who they would like to come back as if they could be reincarnated.
The others gamely tried to answer the question but Bacall snapped: "It's not a fascinating question. No offense."