Background: Sexually transmitted diseases are major global public health problems in both developed and developing countries. Adolescence remains the age group at the greatest risk for acquiring STDs and 50% of them are aged from 15-24 years. Aim of this study was to evaluate the effect of educational guidelines regarding sexually transmitted diseases among male nursing university students. Quasi-experimental pre-post -test design was utilized to fulfill the aim of this study. A Purposive sample of a total 108 male nursing students which included 75 in 1st academic year & 33 in 2nd year at Faculty of Nursing Benha University. Data were collected through a structured interviewing questionnaire. Results: the present study showed that 37.0% of students aged from 19 years old, with the mean age of (19.20±.78251).The present study showed that 46.3 % of them had a history of STDs. Regarding barriers that prevent health seeking behaviors among the study sample, 41.7% of these didn't consult doctor because of shyness. Conclusion: the current study found that there was a highly statistically significant difference related to all items of knowledge regarding STDs pre -test and immediately after program implementation (P< 0.001**). Recommendation: Application of continuous comprehensive health education programs is recommended for students in different grades to focus on STDs with implementation of a practical training course to improve the nursing students' knowledge.