In August 1944, eyespot (Cercosporella herpotrichoidesFron.) was found in ninety out of 121 autumn‐sown wheat crops distributed over twelve Scottish counties. It was abundant enough in forty fields to be likely to harm subsequent crops, and was causing obvious loss in eleven crops. The disease was found in seventeen out of eighteen spring‐sown barley crops, more than half the straws being infected in seven of them. About 4 % of the wheat inspected was lodged mostly by eyespot and about 38 % of the barley mostly non‐parasitically. Eyespot increased with the frequency of wheat and barley in the two preceding years, but a few infected crops occurred on fields where no wheat or barley had been grown for many years. In Scotland, where the atmosphere is more humid, eyespot tends to increase more rapidly than in similar rotations in England; lesions are found higher up the straw and the disease is much more prevalent on spring‐sown barley. The long rotations practised in Scotland prevent more extensive damage by