Preheat oven to 350 degrees F (175 degrees C). Place chicken breast halves on a medium baking sheet.

Bake in the preheated oven 20 minutes, or until no longer pink. Remove from heat, cool and shred.

Place shredded chicken in a medium bowl, and mix in cream cheese, mayonnaise, Cheddar cheese, green chile peppers and jalapeno pepper. Transfer the chicken mixture to a medium baking dish.

Bake uncovered in the preheated oven 30 minutes, or until the edges are golden brown.