Background: Unsuitable reproductive outcomes and human health may be related to various environmental and lifestyle variables. Therefore, helping infertile women and increasing their odds of pregnancy may begin with changing fertility-related behaviors. Aim: The aim of this study was to find out the impact of a maternity nurse-led lifestyle coaching program on health-promoting behaviors among infertile women. Design: This study employed a quasi-experimental research design with two groups (pre-test and post-test). Setting: In the Menoufia Governorate, the study was carried out at the obstetrics and gynecological department outpatient clinics at University Hospital and Shebin El-Kom Teaching Hospital. Sample: For this study, 150 infertile women were chosen as a purposeful sample. Instruments: The three main data collection tools were a structured interview questionnaire, a lifestyle assessment questionnaire, and a health-promoting lifestyle profile. Results: The overall mean score of the health-promoting lifestyle profile domains like interpersonal relationships, stress management, physical activity, nutrition, spiritual development, and health responsibility relationships in infertile women under study increased post-coaching program compared to those who received the conventional intervention. Additionally, the clinical pregnancy had occurred among nearly one-quarter of the studied women in the study group who received and followed the coaching program guidelines compared to the control group Conclusion: After completing a lifestyle coaching program supervised by a maternity nurse, the infertile women in the study showed higher scores for health-promoting behaviors than those who got the traditional intervention. Recommendations: Maternity nurses' lifestyle coaching program should be clinically applicable and integrated into the daily routines of infertile women.