BackgroundHealthcare workers including physicians, dentists, nurses and laboratory workers are considered to be among the groups at the risk of blood-borne pathogen transmission. Thus, it is necessary to evaluate the Knowledge, Attitude, and Practices (KAP) of dentists regarding infection control and basic principles.MethodsThis cross-sectional study recruited 106 dentists in Sanandaj, Iran. The dentists’ KAP regarding hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV/AIDS were evaluated. Chi-square test, student’s t-test, and one-way ANOVA were used to assess differences between the groups. Data were analyzed in Stata 12.ResultsThe results showed that the majority of the subjects in the study population (53.8%) were female. The mean ± standard deviation (SD) for age and work experience was 39.6 ± 9.80 and 10.6 ± 8.7 years, respectively. The mean ± SD for knowledge, attitude and practices of participants was 37.3 ± 3.01, 22.9 ± 4.80 and 24.07 ± 5.06, respectively. The results also indicated that dentists’ higher level of knowledge about HBV, HCV and HIV/AIDS was significantly influenced by work experience (≥10 years; P < 0.001) and graduation year (after 2006: P < 0.001). Positive attitude towards HBV, HCV and HIV/AIDS was considerably influenced by age group (< 30 years: P = 0.021), work experience (≥10 years: P < 0.001), and workplace (dental office: P = 0.016).ConclusionsThe results of this study demonstrated a satisfactory level of knowledge and attitude of dentists about HBV, HCV and HIV/AIDS infections, but some gaps were observed, suggesting that higher knowledge level of dentists plays a very important role in forming the attitudes and practices regarding patients with HBV, HCV and HIV/AIDS.Electronic supplementary materialThe online version of this article (10.1186/s12903-018-0685-1) contains supplementary material, which is available to authorized users.