Potato tubers showing vascular discoloration and bacterial ooze were observed at Lonquén, near Santiago, in May 1982. Plants grown from these tubers showed wilting and chlorosis. Pseudomonas solanacearum was consistently isolated from tubers and diseased plants. Potato leaves, tubers and plants, and tomato plants developed the symptoms when artificially inoculted by differeni methods. The bacterium was reisolated from the infected materials. Bacterial wilt of potato, caused by Pseudomonas solanacearum, is reported for the first time in Chile.