Background: Dental students are at great risk of cross-infection and accidental sharp injuries. Sharp injuries are the main risk for viral infections' transmission such as HBV, HCV, and HIV. The hazard of sharp injuries is generally reduced by following the proper safety measures in clinical training, and student vaccination particularly HBV vaccine. Aim: this study was conducted to evaluate the knowledge about infectious diseases transmission, HBV vaccination status, attitude, and practice of treating patients with infectious diseases,history of occupational injuries, and post exposure management among 4^th and 5^th grades dental students in the Faculty of dentistry in both Mansoura and Delta universities. Method: Atotal of 798 dental students in 4th and 5th grades in both universities were chosen randomly and participated in this cross sectional study. A self-administered questionnaire was designed to evaluate the knowledge, attitude, and practice of dental students toward infectious diseases that transmitted during dental procedures, post exposure management and their vaccination status. After data collection, they were analyzed using (SPSS) program. Results:Mansoura University students had significantly higher correct knowledge about salivary diseases transmission. As well as, significantly higher percentage of Mansoura dental students (90.1%)were vaccinated against HBV Compared to (82.7%) of Delta dental students.On the other hand, both Mansoura and Delta students had correct knowledge about taking medical history and post exposure management without significant difference between them. Mansoura University students had significantly higher attitude towards treating patientswith infectious diseases (89.5%) in comparison to Delta university students (85.4%). But, they had lower practice.  Conclusion: Dental students in both Mansoura and Delta Universities had lower level of knowledge about salivary diseases transmission. But, the majority of them were vaccinated against HBV. In contrast, they had high knowledge and attitude toward treating patients with infectious diseases but moderate practice.