We study electronic as well as phononic transmission through graphene nanoribbons (GNRs) including edge disorder. Electronic transport through GNRs with armchair edges are known to be very sensitive to edge disorder. On the contrary, zigzag GNRs have more robust electronic transport properties near the Fermi energy, except that a transport gap opens. We analyze electronic and phononic transmission through zigzag GNRs depending on the width and the length of the sample. The mean free paths are calculated and the possibility of thermoelectric applications are discussed.