Preheat oven to 350 degrees. Grease an 8 inch square pan very well.
Mix together graham cracker crumbs, chocolate, and nut meats. Blend in sweetened condensed milk. Pour into an 8 inch square pan that has been greased and bottom lined with waxed paper. Bake in a moderate oven (350) until top is golden brown, about 40 minutes. Remove from oven. Allow to remain in pan for 10 minutes. Turn out from pan; remove waxed paper. While still warm cut in squares or bars. Cool.