Knowledge on health and disease prevention and adolescent satisfaction from the health care system are factors that can affect the adolescent's health status. To assess the sources of health information of adolescents in a sample of teenagers from Athens and Crete, Greece. Data were obtained from a convenience sample of 369 adolescents aged 12-18 years from urban areas of Athens and Crete, Greece. Data on health care information sources and overall adolescent health literacy were collected with the use of a questionnaire exploring education on health topics over the past year, sources of health information, and interaction with their physician. More than half the study participants indicated having received information within the past year on oral health, sexually transmitted diseases, physical activity, smoking, and nutrition. The family (71.8%) and the physician (51.5%; boys vs. girls: 44.2% vs. 57.9%, p = .009) are most usually consulted for health information. Girls were found to seek out more sources of health information than boys and to receive more information from their friends (26.9% vs. 11.0%, p < .001), magazines (23.4% vs. 15.1%, p = .046), other health professionals (boys vs. girls: 11.2% vs. 5.8%, p = .068), and pamphlets (boys vs. girls: 21.3% vs. 9.9%, p = .003). A large percentage of adolescents, especially boys, are insufficiently informed on major health issues. Health education programming for youth in Greek schools is imperative to promote healthier lifestyles and to prevent chronic and infectious diseases.