Nelly wanted to work with Nicki Minaj because she is so "dope".
The 38-year-old rapper asked the former 'American Idol' judge to join him and Pharrell Williams on his latest single, 'Get Like Me', and Nelly says she "killed it" on the record.
He said: "Me and Pharrell have a history, we've worked together since the beginning of my career and we thought that Nicki would be dope for this project. It was a dope record and we wanted to add someone different, put a little punch in it and she was perfect. She killed on the record."
Nelly's new album 'M.O' is set for release in September and he believes it is a "step ahead" of all other music out there.
Speaking on the red carpet at the BET Awards 2013, he exclusively told BANG Showbiz: "I'm really excited about it. It's a step ahead of where I feel like everything is at in music right now.
"It's like when I first came in, I felt like I brought a different energy, a different sound that wasn't in at that time. I think I'm doing the same thing on this album, I'm changing it up.
"The thing I've learned from people who have been in this industry ahead of me, like Snoop, Jay-Z, Dr. Dre, is to have longevity you have got to have versatility. You've got to be able to change and adapt.
"Evolution is inevitable, you're going to change no matter what. As soon as you think you control the game and you got it unlocked, that's when you start losing."
While Nelly has worked with a number of huge stars including Justin Timberlake and Kelly Rowland during his career, he chooses people based on their passion for music rather than their fame.
He explained: "I don't have a wish list of who I want to work with, it's about who fits with the song. I just want to work with people who love what they do, who are passionate about it and have an understanding about music."
The BET Awards 2013 is repeated in the UK on Sky 187, Virgin 184 and Freesat 140 this weekend.