1. Preheat oven to 350 degrees.
2. In a large bowl, beat butter, sugar, eggs, and vailla until light and fluffy. Combine the flour, cocoa, baking soda, and salt; stir into the butter mixture until well blended. Mix in the chocolate chips and walnuts. Drop by rounded teasponfuls onto ungreased cookie sheets.
3. Bake for 8-10 minutes, or just until set. Cool slightly on the cookie sheets before transferring to wire racks to cool completely.