Preheat oven to 350°F (175°C).
In a large bowl, cream together the butter, granulated sugar, and brown sugar until smooth.
Beat in the eggs one at a time, then stir in the vanilla and peppermint extracts.
In another bowl, combine the flour, baking soda, and salt; gradually stir into the creamed mixture.
Fold in the chocolate chips.
Drop by rounded teaspoonfuls onto ungreased cookie sheets.
Bake for 10 to 12 minutes, or until edges are nicely browned.
Cool on baking sheets for a few minutes before transferring to wire racks to cool completely.