A panel study of 543 Japanese college students was conducted before and after the Atlanta Olympics in 1996 to explore the impact of the Olympics on the images of foreign countries. In general, the images of 17 countries including Japan have changed favorably after the Olympics. The more they have exposed themselves to Olympic reports on the media, the more they have changed the images. Individual differences had a small, but negative effect. For example, those who were not satisfied with the result of the Olympics tended to change the images unfavorably. Though the perception of similarity between Japan and each country has also increased through the Olympics, the correlation of the index of positive image and the perception of similarity was not high. It suggested that the images of foreign countries and the perception of similarity could have changed through respective processes.