Background: Hepatitis B is one of popular health problem and is considered as major global infectious hazard. It represents an occupational risk for all people who are working in healthcare, including doctors, nurses, laboratory staff, and training interns as well as the student who is trained in hospitals. This can be correlated with their contact with body fluids during clinical rotations and activities. However, protection from getting any infection logically is mandatory for healthcare worker. Aim: Our problem in this study was to assess how our new doctors in Saudi Arabia, specifically those in Riyadh Region and Eastern Region are safe and are protected from hepatitis B infection by evaluating their knowledge, attitude and practice towards Hepatitis B. Method: That was a cross-sectional study which was conducted to intern doctors in Riyadh and Eastern Regions. Random sampling technique was used to select 350 intern doctors. Study tool was a self-administrated questionnaire that is made online by using Google drive forms and sent as an internet link to all interns via WhatsApp mobile application. Data analysis was done using computer application SPSS 24. Comparison between results and many variables was done using Chi-Square test and statistical significance is considered when P-Value < 0.05. Result: In this study, 131 intern doctors participated out of 350 who received the questionnaires (response rate 94.6%). Regarding the level of knowledge, attitude, and practice, around 86% of participants have good knowledge, 63% of them have a positive attitude and 85% have a good practice. Chi-Square test was applied to compare our results of KAP with gender and region. No difference between males and females was found in the level of knowledge and attitude (P-value > 0.05). Males were better than females in practice (P < 0.05). Intern doctors in Riyadh region were better than those in Eastern region in knowledge and attitude (P-value < 0.05), no difference was found between them in practice (P-value > 0.05). Conclusion: It was obvious that our new doctors in Eastern and Riyadh regions have good knowledge, attitude and practice for Hepatitis B. People in Eastern region have less knowledge and attitude compared to those in Riyadh with a significant difference between them. Also, males interns have a better practice than females interns in general.