The current research aimed at exploring the effectiveness of a training program based on using constructive thinking skills in decreasing psychological defeatism levels among university students and their tendency towards intellectual extremism. Twenty (20) university students participated in the research and were distributed into an experimental group (n=12) and a control group (n= 8). The training program, the psychological defeatism scale, the tendency towards intellectual extremism scale (, and the constructive thinking scale were applied to the participants. The researcher utilized the quasi-experimental research design. Throughout processing the data statistically using the Mann-Whitney and Wilcoxon test, the results of the research revealed the following: there were statistically significant differences between the experimental and control group members' mean ranks of scores in the (psychological defeatism scale and its components, and the tendency towards extremism scale and its components) after applying the program in favor of the experimental group, there were statistically significant differences between the experimental group members mean ranks of scores in the (psychological defeatism scale and its components, and the tendency towards extremism scale and its components) in the pre-and post-measurements in favor of the post-measurement, and there were no significant differences between the mean scores of the experimental group in the post and follow-up measurements of (psychological defeatism scale and its components, and the tendency towards extremism scale and its components) a month later.
