The study seeks to investigate the effect of outdoor education camp toward group cohesion among second year undergraduate teacher trainees from selected Teacher Education Institutes of Malaysia. A pre-test and post-test approach with non-equivalent control group was utilised among 350 second year undergraduate teacher trainees from four selected campuses. A modified version of Group Environment Questionnaire (GEQ) was used to gather data from pre-test and post-test. Results from MANCOVA procedures suggested that the camp had positively improved the group cohesion aspects of the experimental group with significant gain in ATG-T, ATG-S, GI-T and GI-S. Furthermore, results also highlight the improvement of group outcome aspects (GI-T and GI-S) which surpassed individual aspects (ATG-T and ATG-S). Overall, the results of this study showed that outdoor education improves teacher trainees' group cohesion.