Purpose: To assess the knowledge of dental decay among pregnant women and its relationship with sociodemographic characteristics and caries experience in rural India. Materials and Methods: A cross-sectional study was conducted among 381 pregnant women in southern India. Variables and knowledge of dental decay were recorded using a structured self-administered questionnaire. Dental caries was recorded by a calibrated examiner as per WHO guidelines. Results: The majority of the respondents were under 30 years of age (91.6%), utilised a public health-care delivery system (57.2%), were primigravid (63%), had a pre-universtiy diploma (64.8%) and were in the 3rd trimester (63%). Overall, poor knowledge was expressed by 12% to 37% of the women. The mean (±SD) DT (decayed teeth), MT (missing teeth), FT (filled teeth) and DMFT (decayed, missing and filled teeth) were 3.08 (±2.6), 0.93 (±2.23), 0.39 (±1.14) and 4.4 (±3.56), respectively. There were no significant differences in the responses to the knowledge of caries with respect to age and trimester. Educational status, health-care delivery system and number of pregnancies had a significant association with knowledge of caries. Conclusion: This study highlighted the limited knowledge of dental decay among pregnant, rural, southern Indian women. Preventive programmes for pregnant women should be designed based upon a thorough interview including an informative session on the specific risks during this period, in order to motivate the patient towards oral health and implement the needed prophylactic measures. Keywords: dental caries, India, knowledge, pregnancy