Background: Psoriasis is a chronic recurrent immune-mediated inflammatory disease with both a physical and psychosocial burden. Patient education is an integral part of comprehensive psoriasis management plan. Aim: To evaluate the effect of nursing guidelines on knowledge level of psoriatic patients. Design: A quasi-experimental research design was utilized. Setting: This study was conducted at Dermatology, Venereology and Andrology department and outpatient clinics at Mansoura University Hospital. Subjects: A purposive sample of 70 adult patients was recruited and divided randomly into two equal groups. Tool : One tool was used to gather data (I): A structured interview questionnaire sheet which is composed of three parts; Part (1): Demographic characteristics, Part (2):Health relevant data, and Part (3): Psoriasis knowledge questionnaire. Results: Study group who received nursing guidelines had higher levels of knowledge than the control group with statistically significant differences between both groups (p<0.001).Conclusion: This study confirmed the efficiency of nursing guidelines in improving psoriatic patient's knowledge. Recommendation: Availability of standardized colored booklet about psoriasis guidelines for patients.