This study conducted a meta-analysis of computer-based and paper-and-pencil administration mode effects on K-12 student mathematics tests. Both initial and final results based on fixed- and random-effects models are presented. The results based on the final selected studies with homogeneous effect sizes show that the administration mode had no statistically significant effect on K-12 student mathematics tests. Only the moderator variable of computer delivery algorithm contributed to predicting the effect size. The differences in scores between test modes were larger for linear tests than for adaptive tests. However, such variables as study design, grade level, sample size, type of test, computer delivery method, and computer practice did not lead to differences in student mathematics scores between computer-based and paper-and-pencil modes. (Contains 5 tables.)