Bad Boy Crew: All the beef was sparked by the shooting in the Manhattan Studio in New York. Pac claimed and told an interviewer of Vibe magazine that it was setup by Biggie (Notorious BIG) and Puffy (Sean Puffy Combs) (Puffy being the mastermind). Basically, Pac had serious beef with Bad Boy Records and was clear to show his anger in his lyrics - "If you wanna be down with Bad Boy, then f**k you too!.."

• Notorious B.I.G. (Biggie Smalls): They were once good friends & Pac was claimed to be the source of Biggie's fame and riches. Tupac would do performances with BIG to assist BIG in his struggling career to be known as a rap star. When Pac was shot in the Manhattan Studio in NY, he claimed that Biggie was aware that the shooting would take place, but failed to give him full information. Their friendship was later worsened when BIG released an album that was remarkably similar to Pac's upcoming album, which resulted in Tupac re-recording the entire new album. Pac also mentioned that Biggie was "rapping about my life" when he was rapping about the cash,,jewelry and assets he did not really have.
• Puff Daddy (Puffy): Tupac had problems with Puffy as he believed he was the mastermind behind the NY shooting. Other (and a more simpler) reasons was because he was down with Bad Boy Records, and he was "fake" or unoriginal as he did not make his own lyrics or music. Some words of retaliation include: "Puffy weaker than a f*cking block I'm running you ni**a..." - Hitemup

Mobb Deep: With the recording of "New York, New York" with Tha Dogg Pound on the album titled, "Dogg Food", the heat between the two rappers was bought to light. Other influences included the fact that Mobb Deep released a song titled "Thug Life, we still livin' it" after he wrote an article about quitting Thug Life. Mobb Deep was believed that he said alot of things in his music that he did not carry out. "Oh yeah Mobb Deep, you wanna f*ck with us? You Little young a** mutha f*ckas, don't one of you ni**as got sickle-cell or something?  You f*cking with me, ni**a ? You f*ck around and catch a seizure or a heart-attack.  You better back the f*ck up before you get smacked the f*ck up, that how we do it on our side.." - Hitemup

Jay-Z : Jay-Z was the first to diss Tupac when he released the track titled "Brooklyn's finest" (with Biggie also dissing him in the same track). Jay-Z had a close relationship with Bad-Boy records and with Mobb Deep. As a retaliation, 2Pac released "Bomb First" on his makaveli album, dissing Jay-Z and others.