According to wikipedia, Paul Calderon was considered to play Jules.

According to NME's 'Nevermind 15th Anniversary' Issue, Cobain and Love were originally offered the part of Lance the dealer and his wife.

According to wikipedia, Joan Cusack was considered to play Mia.

Daniel Day-Lewis was considered for the role of Vincent Vega.

Tarantino reportedly wrote the part of "Butch" for Matt Dillon but the studio feared that the movie should have at least one bankable name on the cast (Travolta was still in a slump) so Tarantino gave the part to Bruce Willis.

Pam Grier auditioned to play Lance's wife. Tarantino did not choose her because he could not envision Grier as a timid character.

Sid Haig was originally asked to play Marsellus Wallace, but declined.

According to wikipedia, Daryl Hannah was considered to play Mia.

According to NME's 'Nevermind 15th Anniversary' Issue, Cobain and Love were originally offered the part of Lance the dealer and his wife.

The role of Vincent Vega was actually written for Madsen. Madsen played "Vic Vega" in Reservoir Dogs and it is rumored that the same character was supposed to be in Pulp Ficiton too until Madsen declined and the role was changed to "Vincent."

Pfeiffer was strongly considered to play Mia Wallace.

Isabella Rossellini was considered to play Mia.

Mickey Rourke was given the oppurtunity to play "Butch" in Pulp Fiction, but turned it down to continue his boxing career.

Meg Ryan was considered for the role of Mia.

According to wikipedia, Christian Slater was considered to play Pumpkin.

Sylvester Stallone was considered for a role - either Butch or Vincent.