A lossless moving picture encoding and decoding method and apparatus are provided by which when intra prediction of a block with a predetermined size is performed, the compression ratio is increased by using a pixel in a block to be predicted. The lossless moving picture encoding method includes: predicting each of pixel values in an M * N block to be predicted by using a pixel in the M * N block closest to the object pixel value in a prediction direction determined by an encoding mode; and entropy coding a difference between the predicted pixel value and the pixel value to be predicted. According to this method, the compression ratio becomes much higher than that of a conventional lossless encoding method.