During the period 1984 to 1987, postmortem brain tissues were obtained in 23 samples of pathologically confirmed ovine scrapie in Japan. Although most of them were collected from Hokkaido, some brain tissues originated from Yamagata, Fukushima and Kanagawa. Occasional incidences of temporal and spatial clustering on a non-familial basis have been reported in the past, each case of which included a small number of sheep centers in Hokkaido and Fukushima. This geographical and temporal clustering, however, did not apply to the present cases with a few exceptions. Ninety percent of those incidences indicated a familial association. A majority of the diseased sheep were from Suffork strain, while three cases were from Corriedale strain. It is very likely that sheep-to-sheep transmission of scrapie has taken place in Obihiro, Hokkaido, Japan.