Background: Hysterectomy is a difficult operation that affects sexual function and alters women's health behaviors and its effect in these aspects has received less attention. One of the nursing models used in improving sexual function and adaptive behaviors after surgeries is Roy's adaptation model. Aim: The present research aimed to evaluate the effect of the nursing approach based on Roy's adaptation model on sexual function and health-promoting behaviors of women after hysterectomy. Design: A quasi-experimental research design (Two-Groups, Time series pre /post-test quasi-experimental design) was used. Sample: A purposive sample of 90 women after hysterectomy operations. Setting: The present research was conducted at Obstetrics and Gynecology department and the outpatient clinics at Benha university hospital. Tools: four tools utilized included: self-administered questionnaire, Female Sexual Function Index, Roy Adaptation Model scale and Health Promoting Lifestyle behaviors. The Results: After three and six months of the intervention, the study group's mean scores for Roy's Adaptation Model, healthpromoting behaviors, and overall aspects of female sexual function were higher than the scores in the control group with highly statistical difference. Additionally, nearly two-thirds of the research group satisfied of Roy's adaption model for hysterectomy. Conclusion: the implementation of the nursing approach based on Roy's adaptation model had a highly significant improvements in women' sexual function, the women became highly adapted with hysterectomy and showed high level of health-promoting behaviors scores related to hysterectomy in (three and six months) after the intervention among the study group as compared to the control group. Which achieved the current study aim and hypotheses. Recommendations: Provide post-hysterectomy instructional guidelines to promote adaptation to sexual problems after hysterectomy.