Abstract-The current study aimed to examine the relationships between academic self-efficacy, the Big Five personality traits (extraversion, agreeableness, conscientiousness, neuroticism, and openness), and academic procrastination among undergraduate students. Two hundred and seven undergraduate students in Semarang participated in this study. A hundred and four were sophomores and 103 were third-year students. The results showed that academic self-efficacy and the Big Five personality traits predicted academic procrastination significantly (R=0. 815, F=65.874, p<0.01). Correlation analysis revealed that academic self-efficacy, extraversion, conscientiousness and neuroticism emerged as the predictors of the academic procrastination tendencies among undergraduate students. Neuroticism and extraversion had a positive significant relationship, while conscientiousness and academic self-efficacy had a negative significant association. Furthermore, the hypotheses about relationships between other personality traits (agreeableness and openness) with academic procrastination were not supported. Agreeableness and openness were not related to academic procrastination. Implications of academic self-efficacy and Big Five personality traits measures to the predictions of academic procrastination among undergraduate students are discussed.