Objectives The purpose of this study was to identify the prevalence and predisposing and etiologic factors of dentin hypersensitivity (DH), as well as the demographic characteristics of patients. Materials and methods The 1210 patients were examined. The research was based on a two-step investigation: questionnaire and clinical examination. DH was evaluated by the response of the patient to tactile and air-blast stimuli. Loss of attachment and gingival recession of sensitive teeth was measured on the buccal and lingual surfaces. Also, the tooth wear of sensitive teeth was graded on the buccal and lingual surfaces. Comparisons of nonnormally distributed continuous variables were performed using the Mann-Whitney U test and Kruskal-Wallis one-way analysis of variance (ANOVA) and Dunn's post hoc test. Comparisons of categorical variables were performed using Pearson's chi-square, Fisher's exact chi-square, Yates's chi-square, and the Monte Carlo chi-square test. Results One hundred twenty-four patients reported DH, showing a prevalence for self-reported DH of 10.2%. Eight hundred forty teeth were diagnosed as having DH, giving a clinical diagnosis rate of DH of 29.4%. Females (76.8%), the 31-40 years age group (26%), housewives (36.8%), and high school education level (38%) had the highest prevalence of DH as demographic properties. A cold stimulus was the most common stimuli trigger for hypersensitivity (97.1%). Occasional pain (55.5%) showed the highest prevalence in terms of frequency of DH. A higher rate of DH was found with the use of medium brushes (47.4%) and brushing twice per day (59.4%) for 1-2 min (56.2%) with the circular method (33.8%) as oral hygiene habits. The buccal surface of the lower right central incisors (5.7%) had the highest prevalence. The most affected teeth by DH were incisors (38.4%). The buccal surfaces (86.3%) of teeth showed a higher high prevalence of DH compared with the lingual surface (52.7%), similar to gingival recession (40.9% vs. 15.7%) and loss of attachment (68.3% vs. 42.6%). Conclusions Clinically diagnosed DH was more common than self-reported DH. Some factors related to patients such as sex (female), the 31-40 years age group, housewives, high school students, using medium brushes, brushing twice per day, and the circular brushing method were more likely to have a risk for DH. Also, buccal surfaces of teeth, gingival recession, and loss of attachment on the buccal surface of teeth should be considered as predisposing factors for DH.