Purpose: The purpose of this study was to compare the levels of knowledge on 5 diseases between persons in hearing impaired and normal hearing groups. Method: The participants consisted of 44 people who are hearing impaired and 47 who are not. An instrument developed by the research team was used for data collection. The questionnaire consisted of 90 items including demographics and items on 5 diseases, hypertension, cancer, diabetes, pulmonary tuberculosis, and hepatitis. Results: The level of knowledge on the 5 diseases, hypertension, cancer, diabetes, pulmonary tuberculosis, and hepatitis in normal hearing group was significantly higher than hearing impaired group. Conclusion: More attention and comprehensive educational programs are needed for people with hearing impairment.