This study was conducted to investigate selection criteria of health information and utilization pattern of health information on the Web by the consumers. Data were collected through off-line and on-line surveys. The off-line survey was conducted with 64 white color office workers in seven companies. The on-line survey was conducted on JoongAng Ilbo 'Healthcare' and KIHASA 'Healthguide' Web sites and 216 participated in the survey. To compare the selection criteria of the consumers with that of health informatics experts, an e-mail survey was done with twenty-six health informatics experts. Selection criteria of health information rated by consumers were in order of accuracy of content, scope and depth of content, privacy and confidentiality, and readability. Experts ranked in order of accuracy of content, purpose of sites, scope and depth of content, and readability. Seventy eight percent of consumers used the Internet once a month to search health information, 60.4% visited health-related Web sites via Internet search. The majority (85%) visited 2-5 different Web sites when they searched for health information. Eighty three percent of consumers regarded the health information on Internet as reliable. Ninety percent of consumers said that the health information on Internet was useful. Consumers used the Internet 'to find disease-related information' (86.1%), 'to find information on exercise and nutrition' (77.9%), 'to get an on-line advice' (42.5%), and 'to buy products or medicine for health' (18.9%). The results of the present study suggested what the health informatics experts should consider when they provide health information on the Internet and what consumers demand when they filter quality health information.