The study investigated the effect of activation and negative affect on self-regulation. The activation factors are self-determination, disengagement, initiative, and persistence while negative affect is composed of worry, anxiety, thought suppression, and fear of negative evaluation. Separate measures were used for each factor and administered to 1454 collegiate students. A time-wave design was used where the activation and negative affect factors were administered in the first wave and the self-regulation in the second. It was hypothesized in the study that the effect of negative affect on self-regulation can be moderated by levels of activation factors. Three models were tested using Structural Equations Modeling (SEM) to determine which structure of negative affect and activation best generates self-regulation. The results show that activation and negative affect each differently affect self-regulation, p less than 0.001 (RMSEA=0.054, X[superscript 2]=505.43, GFI=0.96). Negative affect can increase self-regulation when mediated by activation, p less than 0.001 (RMSEA=0.056, X[superscript 2]=527.22, GFI=0.96). The effect of negative affect on self-regulation is weak if individuals posses high activation levels, p less than 0.001 (RMSEA=0.05, X[superscript 2]=309.64, GFI=0.97). The theoretical and educational implications of the findings are discussed. Eleven appendices are included: (1) Self-regulated Learning Interview Schedule; (2) Action Control Scale; (3) Perceived Self-determination; (4) Academic Emotion Questionnaire; (5) Fear of Negative Evaluation; (6) Penn State Worry Questionnaire; (7) White Bear Suppression Inventory; (8) Three-Factor Measurement Model; (9) Two-Factor Measurement Model; (10) Negative Affect and Self-regulation in One Latent Factor; and (11) One-Factor Measurement Model. (Contains 5 tables and 8 figures.) [Research grant for this paper was provided by the De La Salle University Research and Coordination Office.]