Objectives: To determine the awareness of hepatitis B infection among firstt year college students of medical, nursing and community service of Dammam University and, to compare the knowledge level between them. Methods: A descriptive cross-sectional study was conducted on 485 first year medical nursing, and community service students of Dammam University (Eastern Province of Kingdom of Saudi Arabia). A self-administered questionnaire was distributed to all the students and their awareness on the definition, modes of transmission, diagnosis, complications, treatment availability and prevention of hepatitis B was obtained. [The data was entered and analyzed using SPSS 16 for Windows. Descriptive statistics with cross-tabulation were performed. The Chi square - test, and t-test was used]. Results: Overall, 420 (86.6%) students correctly defined hepatitis B and 76.9% knew about the types of hepatitis. A majority of the students believed that hepatitis B was blood-borne but there was poor awareness about other modes of transmission. Less than one-fourth of the students knew about needle-stick injury from an infected patient, drug abuse, careless dental procedures and mother-to-child transmission of the disease. Prevention of the disease by vaccination was known to only 54.4 % of the students. Conclusion: The present study concludes that the majority of the students lacked knowledge regarding important modes of transmission. They also had poor knowledge about the complications and prevention of hepatitis B. Health education needs to be given to all students regarding this subject.