20704 Background: The use of Internet as a source of medical information by cancer patients has not been widely studied. Our purpose was to examine the kind of information collected from the web by cancer population as well as the barriers to its use, degree of satisfaction and its effects on the relationship between patient and clinician. Methods: Between June 2006 and September 2007, 109 patients (pts) and 67 relatives were approached in a tertiary hospital and two national health clinics. Ninety-nine patients and 66 relatives completed a structured interview. Information requested included social and demographic data, cancer specific questions and subjective perceptions after the searching the web. Results: 18.2% of pts and 66.7% of cancer relatives used Internet for searching medical information, being the more requested enquiries those concerning general information about the disease (88.2% and 52.9% among pts and relatives respectively) and treatment options (47% of pts and 41.2% of relatives). 77.8% estimated that the search had not helped them in making decisions, though 66.7% considered it had been useful in someway. The main reason for not using the web among pts was their preference to obtain it from physicians (44%) and, secondly, the lack of access to a computer (33.9%); among non users, 45.2% would have desired to have the chance. Regarding the degree of satisfaction, 33% of pts and 46% of relatives felt more confused. Only 11% of patients had discussed the findings with the physician, though from them the 85.7% considered the discussion had been of any help. Conclusions: The use of Internet to obtain cancer related information is not very extended in our country, though many patients and relatives would desire to do so. Besides, between users, the degree of satisfaction achieved is low, and only a reduced subgroup discusses the findings with the physician. Therefore, public health authorities should contemplate the elaboration of newer guidelines in the web aimed at cancer population in an effort to improve the information offered. No significant financial relationships to disclose.