Background: Health literacy is defined as the cognitive and social skills which determine the motivation and ability of individuals to gain access to, understand, and use information in ways which promote and maintain good health. This study was conducted to determine health literacy levels and the associated factors among patients attending the outpatient departments of a tertiary care hospital in Delhi. Methods: A hospital-based cross-sectional study was carried out in a tertiary care teaching hospital in Delhi over a period of four months. A total of 150 patients were included in the study. Fifty patients from the Diabetes Clinics, 50 patients from Hypertension Clinics, and 50 patients with anemia from the Antenatal Outpatient Department (OPD) were selected using a convenience sampling method. Data was analyzed using Epi Info software. Statistical analysis was conducted with the chi-square test and the Fisher’s exact test. P values less than 0.05 were considered significant. Results: Out of 50 diabetic subjects, 37 (74%) understood the information about their blood sugar levels as explained to them by the doctor. Similar results were found among hypertensive subjects as well. Furthermore, education status was significantly associated with health literacy. In terms of understanding the regimen of medications, significant association was seen with age, sex, and education. Conclusion: Education status, age, and gender are important determinants of health literacy. Our results support that innovative strategies of communication should be used to improve health literacy among patients.