Many factors affect the academic performance of undergraduate students. Playing videogames among male students vis-Ã -vis their academic performance was assessed in this study. This study employed two hundred and fifty male undergraduate students (250) aged between 15 and 23 (M =17.44, SD=1.37), selected from a Nigerian private University. Academic performance was assessed using Cumulative Grade Point Average (CGPA) collapsed into three groups (viz: 1= 1.25 to 3.49, 2 = 3.50 to 4.49 and 3 = 4.50 to 5.00). Pathological playing of videogames was assessed using the Problem Video Game Playing questionnaire (PVP). A statistical significant difference at the p < .05 level was observed F (2, 250) = 5.15, p = .01. The small effect size of 0.04 was obtained using the partial eta squared. A Post-hoc comparison using Tukey HSD test indicated that group 1 differed significantly in their mean scores from group 2 and 3. Further analysis with Pearson Product Moment Correlation Coefficient showed r = -.262, n = 250, p <.000 and r = .261, n = 250, p <.000 for CGPA and self-reported grades respectively. It was concluded that videogame addiction has a significant effect on the academic performance of male undergraduate students.