To assess the prevalence of dentin hypersensitivity (DH) and etiological factors among undergraduate students from Iraq- Maysan Governorate. 280 students of Al-Manara College for medical science, Iraq, enrolled in a cross-sectional survey. A self-report questionnaire was used for DH diagnosis and confirmed by tactile and evaporative tests clinically. Statistical analysis Descriptive and chi-square test p<0.05 were done. The prevalence of DH in the sample was 19.0%. DH prevalence to the tactile stimulus was higher in those participants whose toothbrush movement was vertical/horizontal (OR = 3.13, 95% CI = 1.27–7.7, p < 0.001), in the female group (OR = 3.01, 95% CI = 1.17–7.7, p = 0.010), in the presence of dental biofilm (OR = 2.8, 95% CI = 0.64–12.29, p < 0,001). When DH was diagnosed by evaporative stimulus, there was a significant association with accumulation of dental biofilm (OR = 4.33; 95% CI = 1–18.73; p = 0.027), gingival recession (OR = 2.15; 95% CI = 1.09–4.23; p = 0.004) on the affected tooth, and with the use of mouth rains solutions (OR = 2.39; 95% CI = 1.01–5.67; p = 0.016). DH registered a high frequency in our sample. Students with DH were more likely to show traumatic dental brushing, the existence of dental biofilm, and gingival recession in the affected teeth.