This study examined the classroom environment correlates of continuing motivation in science for national samples of early and late adolescents. Controlling for achievement in science and student background characteristics, measures of the quality of the classroom social environment, and the utility of science content and classes had significant positive regression weights in both samples with continuing student interest and participation in voluntary science activities. The extent to which teachers, rather than students, controlled the learning environment was negatively associated with continuing motivation. Significant interactions were found between level of achievement in science and two dimensions of the classroom environment. For early adolescents the utility of science content and classes had its strongest positive influence on continuing motivation in science for students at the relatively highest levels of science achievement. A similar interaction was found for the older adolescent sample between science achievement and class morale.A large and growing body of research on the effects of formal schooling has focused on the influence of classroom social environments (e.g., comprehensive reviews by Moos, 1979;Walberg, 1976). The assessment of the The authors thank