Background: Hysterectomy as a gynecological surgery cause heavy psychological pressure and affect quality of life of women. The research aim was to evaluate the effect of applying Bandura's theory of self-efficacy on anxiety, disease uncertainty and quality of life among women undergoing hysterectomy. Design: A quasi experimental design. Setting: Obstetrics and Gynecological department in Benha University Hospital. Sample: A purposive sample of 84 women undergoing hysterectomy divided into two groups. Data collection tools: Five tools were used: A structured interviewing questionnaire, the general self-efficacy scale, the self-rating anxiety scale, sense of disease uncertainty scale and World Health Organization quality of life scale. Results: There was no statistical significant difference in the mean scores of the self-efficacy, anxiety, sense of uncertainty and quality of life between the study and control groups at pre intervention phase (p ˃ 0.05) compared to the higher mean score among study group than the control group with a highly statistical significant difference after three and six months of intervention (p ≤ 0.001). Conclusion: The implementation of self-efficacy theory model was effective in improving level of knowledge, reducing level of anxiety and disease uncertainty and improving quality of life among women undergoing hysterectomy. Recommendation: Self-efficacy theory model should be explained in printed booklets that ought to be available to all women undergoing hysterectomy in every obstetrics and gynecological facility.