Background Nurses play a crucial role in providing effective care for vitiligo patients undergoing phototherapy. Their knowledge and practice about vitiligo care is influenced by various characteristics. Understanding these relationships and educating nurses can guide the development of targeted interventions to improve nurses' knowledge and practice and enhance patient care outcomes. Aim To determine the Effect of Implementing Educational Guidelines on Nurses' Knowledge and Practice toward Caring of Vitiligo Patients Undergoing of Photo Therapy. Research design A quasi-experimental design was used to achieve the aim of the study. Setting The study was conducted in Sheikh Zayed Dermatology Hospital in Ismailia, Egypt. Materials and methods A convenient sample of 40 nurses was recruited. Tools of data collection Two tools were used: Nurses' interview questionnaire sheet, and Assessment Nurses' practices toward vitiligo patients check lists. Results There was a lack in nurses' knowledge before educational guidelines which increased in post and follow-up phases of educational guidelines with a highly statistically significant difference (P< 0.01). As evidence, 22.5% and 30.0% of the studied nurses have satisfactory level of total knowledge at pre-intervention, respectively. While changed to be 90.0% and 95.0% after implementation of educational nursing guidelines, respectively, with a statistically significant difference (P=0.000). Moreover, there was a lack in nurses' practice before educational guidelines, which increased in post and follow-up phases of educational guidelines, as evidence, 12.5% and 22.5% of the studied nurses were competent respectively. While changed to be 90.0% and 95.0% after implementation of educational guidelines, respectively. with a statistically significance difference (P=0.000). Conclusion Based on the results of the study, mean scores of nurses' knowledge and practice were higher in post and follow-up phases of nursing educational guidelines. Recommendation Intervention guidelines toward vitiligo patients should be conducted for nurses, as they are the key to improve nurses' knowledge and practice and enhance vitiligo patient care outcomes.