Toy Story 2 was the Pixar feature-length film released immediately before Monsters, Inc. in theaters.
Toy Story 2 premiered in 1999, while Monsters, Inc. followed in 2001. This places Monsters, Inc. as Pixar’s fourth feature film, after Toy Story, A Bug’s Life, and Toy Story 2. The two films also share Pixar’s expanding focus on emotionally driven stories built around distinctive non-human characters.
A common mix-up is placing Toy Story 2 directly before Monsters, Inc. without counting Pixar’s short films or other studio releases. The question concerns Pixar’s feature-length theatrical filmography, not every animated film released by the company. Pixar’s next feature after Monsters, Inc. was Finding Nemo, released in 2003.