The authors' purpose was to test a parsimonious model derived from social cognitive career theory (R. W. Lent, S. D. Brown, & G. Hackett, 1994) and expectancy value theory (J. S. Eccles & A. Wigfield, 2002) that integrates groups of variables (demographic background, student behaviors, and school-related beliefs) with the goal of predicting high school dropout in a nationally representative sample of 15,753 high school students. Structural equation modeling was used to test the effect of the various predictors on students' dropout status 2 years later. The model fit the data very well, and the results indicated that socioeconomic status, academic performance, parental involvement, and absenteeism were most predictive of high school dropout. In contrast, social cognitive constructs (self-efficacy and subjective task value) added little explanatory power. Implications for high school dropout prevention programs are discussed.