Health Care Workers (HCW) are at high risk of acquiring blood borne diseases. This study compared the risk of infection among HCW in different hospital units and also between HCW and students in medical fields. This cross sectional study involved pre tested questionnaires that were completed by 625 HCW and undergraduate students undergoing clinical attachments from February to August 2001. The respondents were separated into two groups : i) HCW from Hospital Kuala Lumpur, HKL (n=241) and Hospital Universiti Kebangsaan Malaysia, HUKM (n=153) ii) Medical students from Universiti Kebangsaan Malaysia, UKM (n=171) and HUKM student nurses (n=60). The results obtained showed that the risk of transmission of blood borne infections varied significantly according to professional ranks (p