The aim of this study was to assess practices related to diagnosis of dental caries among dentists (n=217) from Araraquara, São Paulo State, Brazil. Data on sociodemographic information and practitioner characteristics were collected using a pretested questionnaire, and data on practices related to caries diagnosis were gathered by using a translated and culturally adapted questionnaire from the US National Dental Practice-Based Research Network. Descriptive statistics and regression analyses were used for data analysis. Respondents reported using in most of their patients radiographs (Rx) to diagnose proximal caries (59%), explorer (Ex) for the diagnosis of occlusal caries (64%) and on the margins of existing restorations (79%), as well as air jet (AJ) with drying (92%). Magnification (M) (25%), fiber optic transillumination (FOTI; 14%), and laser fluorescence (LF) (3%) were used in the minority of patients. Regression analysis revealed that the following dentists' characteristics were significantly associated (p<0.05) with the use of diagnostic methods on a greater percentage of their patients: advanced degree (Rx, FOTI), higher percentage of patients with individualized caries prevention (Rx, FOTI, M), more years since dental school graduation (Ex, M), and work in an exclusively private practice model (LF). In conclusion, most Brazilian dentists from Araraquara reported they most commonly use visual, tactile, and radiographic imaging for the diagnosis of dental caries. Some dentists' characteristics, such as time from dental school graduation and having a postgraduation course, were associated with the use of certain diagnostic methods.