The internet is an important source of healthcare information. To date, assessment of its use as a source of oncologic information has been restricted to retrospective surveys.The cancer-related searches of approximately 361,916,185 people in the United States and the United Kingdom were examined. Data were collected from two separate 100-day periods in 2008 and 2010.In 2008, there were 97,531 searches. The majority of searches related to basic cancer information (18,700, 19%), followed by treatment (8404, 9%) and diagnosis (6460, 7%). This compares with 179,025 searches in 2010 representing an increase of 183%. In 2008 breast cancer accounted for 21,102 (21%) individual searches, increasing to 85,825 searches in 2010. In 2010 a total of 0.2% (321) of searches focused on litigation, with those searching for breast cancer information most likely to research this topic (P = 0.000).Use of the internet as a source of oncological information is increasing rapidly. These searches represent the most sensitive information relating to cancer, including prognosis and litigation. It is imperative now that efforts are made to ensure the reliability and comprehensiveness of this information.