This study examined the impact of Stress Inoculation Training (SIT) program on the state-trait anxiety of 57 high-stress senior college students in one of the colleges in Mindanao. Using purposive sampling and quasiexperimental design with three treatment conditions 1) no training, 2) abbreviated Stress Inoculation Training, 3) standard Stress Inoculation Training, and measured at three points in time: pre-intervention phase, post-intervention phase, and delayed post-intervention phase, multivariate analysis of covariance (MANCOVA) results showed that there was a significant difference between groups on dependent variables post-intervention state anxiety scores (postSAS) and delayed post-intervention state anxiety scores (delSAS) Wilk's λ .84, F (4,104) = 2.45, p = .05. Univariate analysis of covariance (ANCOVA) revealed a significant difference in the post-intervention state anxiety scores F (2, 53) = 4.78, p = .01 with adjusted means significantly lower for the abbreviated Stress Inoculation Training group compared with the no training and standard Stress Inoculation Training groups. Multivariate analysis of covariance results further showed no significant difference between groups on the post-intervention trait anxiety scores (postTAS) and delayed post-intervention trait anxiety scores (delTAS) Wilk's λ = .88, F(4,104) = 1.79, p = .14. Overall, results indicated that abbreviated Stress Inoculation Training effectively reduced state anxiety than standard Stress Inoculation Training. However, its effects failed to show stability over time. On the other hand, neither abbreviated Stress Inoculation Training nor standard Stress Inoculation Training effectively reduced trait anxiety. These findings support the efficacy of abbreviated Stress Inoculation Training over standard Stress Inoculation Training in reducing high-stress senior college students' state anxiety.