The current intervention study was conducted on a group of 130 health care workers (nurses, lab. technicians and workers) working in nine primary health care centers in Cairo and Giza governorates. Their knowledge, attitude and practice concerning blood borne infectious diseases and safety precautions was assessed before and one month after health education. The health education lecture presented a comprehensive message on the three main blood borne infections HBV, HCV and HIV, and the basic safety precautions, and was reinforced by distribution of educational aids like posters, gifts and colorful printed materials. The study showed that the whole group of HCWs had significant improvement in their knowledge, attitude and practice after health education. Nurses showed significant improvement in both knowledge and attitude. The workers group showed significant improvement in their knowledge and practice, while the lab technicians group did not show any significant improvement. The difference in percent change of knowledge between the three study categories was significant and the group of workers showed the highest percent change. There was no significant change in specific aspects of practice. However, the exposure of HCWs to needle stick or blood or body fluid splashes decreased significantly and there was significant improvement in both reporting the exposure to health management and in immediate hand washing after exposure. The study concluded that health education had a significant positive impact on the study population knowledge, attitude and practice. However, some risky practices did not show a significant improvement in spite of the improvement shown in its related knowledge. The study recommended continuous health education courses to health care workers addressing the transmission and prevention of blood borne pathogens with monitoring and following up of the improvement in trainees’ knowledge, attitude and practice.