Thephysicians do not have sufficient knowledge about the prevention of dental caries and the relationship between oral health and general health. To determine the knowledge and attitude of medical interns regarding oral hygiene. This descriptive-analytical study was performed on 55 students or interns of Shiraz University of Medical Sciences. Data about demography and knowledge level of interns of Shiraz University of Medical Sciences were collected about oral and tooth health status by a standard questionnaire. The total awareness score for each person was defined as the sum of questions for each individual. In order to compare the level of knowledge between men and women and different universities, two-way ANOVA test was used. The mean of knowledge of men and women was 68.61 ± 7 and 70.14 ± 81, respectively. Also, this score was among students of national, Azad and international campus universities 69.87 ± 7, 73.05 ± 16, 64.69 ± 4, respectively. According to the statistical analysis, the mean score of total awareness among men and women was not significant. Also, no significant differences were found between the total awareness mean of different universities. Regarding the low score of knowledge of interns in Shiraz University of Medical Sciences about oral health practices, practical training in this field and the practice of referral of patients to the dentist during their education can improve their function.