As in every other segment of the Internet, the amount of health-care information has increased exponentially in the past five years. Research-oriented, clinical-oriented and education-oriented medical resources have been built on the Internet by companies and institutions. Thousands of major medical web sites are currently serving millions of documents on the Internet, which are likely to double in the next 20 months. While the Internet is becoming the largest medical information repository, it is necessary that health-care professionals know efficient ways to find what they want in the vast field of medical information. This paper discusses the categorization, searching mechanisms and the impact of medical resources on the Internet.