Purpose： This study examined the effects of cognitive-behavioral therapy on problem-solving ability and dysfunctional attitudes in undergraduate students. Method： This study was conducted between September 2004 and May 2005. The subjects consisted of 23 undergraduate students. The experimental group (n=13) participated in a cognitive-behavioral therapy that consist of 8 session over an 8-week period. The control group (n=10) participated in a reality therapy that also consisted of 8 sessions over an 8-week period. Problem-solving ability and dysfunctional attitudes were measured for all subjects before and after therapy. These data were analyzed by unpaired t-test and t-test with the SAS program. Results： Following cognitive-behavioral therapy, the experimental group experienced a significant decrease in score of problem-solving ability and in approach-avoidance style (the subscale in the problem-solving ability). There were no changes in these values after the reality therapy in control group. Conclusions： In light of these results, cognitive-behavioral therapy has a positive effect on problem-solving ability in undergraduate students.