Background: Dental caries, commonly known as tooth decay or cavities, is one of the most prevalent oral health problems affecting adolescents worldwide. Dental caries as increased significantly due to changing dietary habits, increased consumption of sugary foods, poor oral hygiene practices, and lack of awareness regarding preventive dental care. Adolescence is a crucial stage of life during which permanent teeth are highly vulnerable to decay because of hormonal changes, lifestyle modifications, and negligence towards oral health. The World health organization reports the burden of oral diseases to be less in developing countries. Despite health sector improvement in India, dental caries has remained among the leading causes of consultation at all levels of the health care delivery pyramid with high numbers in rural communities. The prevalence of dental caries experienced in India is found to be 64.9% but few studies have been conducted assessing the predisposing risk factors, especially in adults. The objectives of the study included the determination of dental caries prevalence and associated risk factors among adult outpatients who attended department of dentistry at Santosh Medical College & Hospital, Ghaziabad. Methods: Hospital-based cross-sectional study using quantitative methods with a sample size of 281 participants aged 18 and above systematically selected randomly without repetition from patients’ registry at reception picking every tenth among patients who attended Santosh Medical College & Hospital, Ghaziabad outpatient department during the study period. The sample size calculation used Yamane’s 1967 formula. Ethical approval was issued by the school of health sciences and informed consents were signed by participants with the right to withdraw at any time without prior justifications. Data collection instruments included a self-administered close-ended questionnaire with questions on sociodemographic characteristics, eating and drinking habits, oral hygiene practices, and smoking habits; and a data sheet to extract data from patients’ files after a physical dental examination of study participants. The study collected information on risk factors for dental caries development that included age, gender, oral hygiene practice, alcohol consumption, sugary snacks, and beverages consumption, and tobacco use. Data were analyzed using a statistical package of social sciences at a 95% confidence interval. Results: The prevalence of dental caries is 71.5% among patients attending the outpatient department and predisposing risk factors were found to be old age, gender, poor oral hygiene, consumption of sugary snacks and beverages. Alcohol was also found to contribute to dental caries development, but no statistical significance was found. Conclusions: The prevalence of dental caries was found to be high in the study population and the multifactorial risk factors associated with its development were found to be poor oral hygiene, frequent consumption of sugary snacks and beverages, gender, and old age. The study recommended further studies to explore these multifactorial risk factors on a larger scale.