This report described an outbreak of blindness caused by hypovitaminosis A in Hanwoo (Korean native cattle) in Gyeongsangbukdo province, Korea. The diagnosis was based on clinical findings, analysis of diet, and concentration of vitamin A and carotene in serum and/or feedstuff. Thirty eight of 48 cows were found to be affected. The causative diet contained higher levels of crude protein, net energy and crude fat and lower level of total fiber and crude fiber. Surprisingly, vitamin A was not detected in the causative diet. Treatment of vitamin A to Hanwoo that had blindness did not induce further progress of the symptom. Furthermore, there were no additional diseases detected. Based on the observations described above, this case was diagnosed as hypovitiminosis A.