Medical students are at high risk of being exposed to blood-borne pathogens. The aim of this study was to identify the levels of knowledge, attitude and practice of medical students regarding standard isolation precautions in Iran. A questionnaire was filled out by 468 medical students in their fifth to seventh year of study. Their mean knowledge, attitude and practice levels of standard isolation precautions were 6.1+/-1.5 (maximum possible score 9), 32.3+/-3.5 (out of 45), and 2.3+/-1.6 (out of 9), respectively. Statistically significant positive correlations were observed between knowledge and attitude, knowledge and practice, and practice and attitude. Ninety percent of medical students in Shiraz had received no education of standard isolation precautions, and 75% of respondents wanted more education on standard isolation precautions. Education on infection control issues should not only be focused on healthcare workers, but should also include medical students.