A method and apparatus for sharpening the knives of a chipper, with the knives remaining in a knife basket during sharpening, and the knife basket being removed from the chipper and placed in a knife basket carrier in which it is rotatably mounted. The knife basket is first locked against rotation, and then a sharpening device, such as a grinding mechanism, is moved in a direction parallel to the knife basket axis along a first knife or group of knives for purposes of sharpening. After sharpening the first knife or group of knives, the knife basket is unlocked and the sharpening device and knife basket are rotated relative to each other, with the sharpening device proceeding to a new working position for sharpening a further knife or group of knives. The above cycle is repeated until all knives have been sharpened. The knife basket is then reinstalled in the chipper.