Language learning motivation is a complex, composite construct, and although past research has identified a number of its key components, the interrelationship of these components has often been subject to debate. Similarly, the exact contribution of the various motivational components to learning behaviors and learning achievement has also been interpreted in different ways. The purpose of this study is to use structural equation modeling to evaluate a proposed theoretical model concerning the internal structure of the second language (L2) motivation complex and its impact on motivated behavior. The basis of the analysis is survey data collected in Hungary from 8,593 pupils, 13 to 14 years old, on two occasions, in 1993 and in 1999. Our main finding is that integrativeness appears to be the single most important factor, subsuming or mediating the effects of all the other responses to questions asked. In light of this finding, we analyze what motivational content this core component might represent in various settings.