<![CDATA[This study investigated the causes and effects of students' absenteeism on academic performance in universities in Delta State, Nigeria. A correlational survey research design was adopted for the study. The population comprised approximately 12,000 undergraduate students, from which a sample of 400 students was selected using a multistage sampling procedure. Data were collected using a researcher-developed Students' Absenteeism and Academic Performance Questionnaire (SAAPQ). The instrument was validated by experts and its reliability was established through Cronbach's alpha. Data were analyzed using frequency, percentage, mean, standard deviation, Pearson Product-Moment Correlation, and simple linear regression at the 0.05 level of significance. Findings revealed that major causes of students' absenteeism included boring teaching methods (M = 3.36), poor personal motivation (M = 3.31), poor time management (M = 3.28), academic workload and fatigue (M = 3.25), and difficulty of some courses (M = 3.24). Respondents also agreed that absenteeism negatively affected academic performance, particularly by causing missed lecture explanations, difficulty understanding course content, poor examination preparation, and lower academic scores (Grand M = 3.34). A significant negative relationship was found between causes of absenteeism and academic performance (r = -.462, p < .05). Furthermore, absenteeism significantly predicted academic performance, R = .518, R² = .268, F(1,398) = 129.58, p < .05, indicating that absenteeism explained 26.8% of the variance in academic performance. The study concluded that student absenteeism is a significant academic concern requiring coordinated institutional interventions. Universities should strengthen attendance monitoring, improve teaching methods, provide counselling, and address students' academic and socioeconomic challenges.]]>
