BACKGROUND: Hypothyroidism causes considerable morbidity. Low knowledge coupled with inadequate health literacy may lead to poor prevention and management. This study aimed to assess health information-seeking behavior and hypothyroid knowledge among South Indian hypothyroid patients. METHODS: This cross-sectional study was conducted in October 2013 in Saveetha Medical College, Chennai, India. Hundred clinically diagnosed hypothyroid patients >18 years were interviewed in a hospital using a 57-item questionnaire to gather information on their socio-demographics, self-reported disease history, hypothyroid-related knowledge, health information sources, health literacy and health information-seeking behavior. Hypothyroidism was assessed by free T3 and T4 levels. RESULTS: Mean age of participants was 38 years (SD=12) with median age of 39.5 years, majority of the participants being females (77%) and living in urban setting (52%). Mean free T3 level was 0.0137ng/dl (SD= 0.003) and mean free T4 was 0.7ng/dl (SD= 0.06). Ninety three percent of the participants received initial hypothyroidism education from their physicians at the time of diagnosis. Half of the participants had incorrect hypothyroidism-related knowledge; similar between both genders. Participants with inadequate health literacy had poor knowledge about the hypothyroidism. Hypothyroidism-related health information was sought almost exclusively from health professionals, predominantly regarding treatment, linked to their faith in qualified medical assistance. Economic status primarily determined healthcare-seeking behavior. Marital status, education level, annual household income and health literacy were significantly associated with knowledge. CONCLUSION: Participants having higher educational qualification, higher annual household income and adequate health literacy had considerable knowledge about hypothyroidism. Developing multifactorial and tailored health education for patients with marginal or inadequate health literacy is needed. Exploring healthcare institutions as a medium for delivery of such education should be explored.