Undergraduate students enrolled in an introductory biology course for nonmajors during the fall semester of 2007 were administered the Biology Attitude Scale (Russell and Hollander 1975), a constructed Mathematics Attitude Scale, and a portion of the Motivated Strategies for Learning Questionnaire (Pintrich and Smith 1993). Together, the instruments assessed attitudes toward biology and mathematics as well as various motivational constructs including self-efficacy, intrinsic motivation, extrinsic motivation, task value, control of learning beliefs, and test anxiety. Final course grades were also obtained. Multiple regression analysis revealed that the significant (p less than 0.05) predictors of course grade (R[superscript 2] = 0.362, n = 312) were self-efficacy (beta = 0.484), test anxiety (beta = -0.211), and math attitudes (beta = 0.094). No other variables contributed to the model. Further multiple regression analysis revealed that the best predictors of self-efficacy (R[superscript 2] = 0.665, n = 318) were biology attitudes (beta = 0.329), control of learning beliefs (beta = 0.280), test anxiety (beta = -0.249), intrinsic goal orientation (beta = 0.166), task value (beta = 0.147), and extrinsic goal orientation (beta = 0.119). Implications including strategies to improve course performance through fostering student motivation and building self-efficacy are discussed. (Contains 4 tables and 2 figures.)