Never one to hold her tongue, Jennifer was speaking during a taping of NBC’s Late Night with Seth Meyers.
Jennifer Lawrence and Miley Cyrus
A source told US Weekly: "Jen said she was so drunk, she puked on the stairs at Madonna's after-party, and Miley walked by and said something like, 'Get it together, girl!'"
The taping, which was recorded on 21 April, will air on 21 May.
The 23-year-old Oscar winner was nominated in 2014 for Best Supporting Actress for her role in American Hustle, but lost to Lupita Nyong’o for her performance in 12 Years A Slave.
Jennifer attended the 2 March ceremony with her best friend – and caused more disruption when she fell over on the red carpet. It was the second Oscars embarrassment for Jennifer, who in 2013 tripped on her way to collect her award for Best Actress.
Party girl Jennifer was spotted in London last week with boyfriend Nicholas Hoult and fashion designer Tom Ford as the trio dined out at the Firehouse Club restaurant.
Jennifer Lawrence at the 2014 Oscars
As they left the North London eatery, Jennifer was seen flashing a bright turquoise ring that had caused a stir earlier that day, as Jennifer and Nick were photographed at a North London pub where the Kentucky-born actress wore what looked like an engagement ring.
Adding to their romantic and jovial appearance, Jennifer and Nick beamed and laughed affectionately with each other throughout the low-key date.
On Tuesday, the pair, who met in 2011 on the set of X-Men: First Class, were reported to have purchased property in London.
Jennifer has fallen in love with the English countryside, said one source, who added: "Jen loves the English way of life and as they are now serious again, it makes sense to look into buying somewhere."