Objectives: This study aimed to determine the effect of educational intervention on the promotion of physical activities of older men based on the trans-theoretical model.

Methods & Materials: This clinical trial was conducted on 140 elderly retired member of the Association of Qom with random selection of properties in the control and intervention groups. The instruments used were researcher-made questionnaire based on trans-theoretical model and Champs elderly physical activity questionnaire. To analyze the results, the Chi-square test and repeated measures analysis of variance were performed using SPSS version 18. This study was approved by the IRCT site (No. IRCT201407208742N5).

Results: Before the study, the intervention and control groups showed no significant differences (P<0.05) in terms of demographic variables and physical activities. Average scores for the elderly physical activities of the intervention group before training, one month, and six months after training were significantly different (P<0.001). The mean score on the questionnaire structure-based model of education in this group had no significant difference (P<0.05). There were no significant differences in the mean scores of physical activity questionnaires of the control group.

Conclusion: According to the findings of this research, educational intervention based on the trans-theoretical model is effective and valid in promoting physical activities, and the trans-theoretical model can be useful in this regard. Application of this model and identifying the barriers and facilitators of physical activities in the elderly can be effective steps towards promoting regular physical activities in these people.