Objective  To evaluate the effect of health education on disease-related knowledge and safe sex in patients with sexually transmitted diseases（STD）. Methods  Seven nurses received professional knowledge and skills training and they provided health education on STD-related knowledge and safe sex，psychological interventions and follow-up service for 362 STD patients in the private consulting room. Results  After intervention，the patients?蒺 knowledge related to the relapse，risk factors，prevention and consequences of STD increased significantly（P<0.01）；their willingness to use condoms increased from 8.01% to 51.66%；the proportion having sex behaviors with spouse increased from 15.19% to 40.88%，with regular sex partner increased from 23.48% to 33.98%，with commercial partners decreased from 31.49% to 11.05%（P<0.01）. Conclusion  Health education can effectively improve the disease-related knowledge and promote safe sex behaviors in STD patients.