Using the Trends in International Mathematics and Science (TIMSS) video study, the authors compare science teaching practices in the United States and in four other countries that outperformed the United States: Australia, the Czech Republic, Japan, and the Netherlands. Their observations of videotapes from 100 8th-grade science lessons in each country revealed two major differences between the higher-achieving countries and the United States. First, each of the higher-achieving countries had a distinct core pattern of science teaching; in contrast the U.S. lessons were characterized by variety. Second, in all the higher-achieving countries, science lessons were content-focused--activities were closely linked to the development of science concepts. The authors recommend that U.S. schools improve their science education by adopting this focus on content. (Contains 1 figure.)