The aim of this study was to investigate the prevalence of Internet usage among cancer patients in seeking health-related information and the type of information sought. Sources of information received from, preferences for information sources and the perceived usefulness of information from these sources were also examined in this study. A self-administered questionnaire was used to evaluate the information needs of patients undergoing cancer treatment. The questionnaire also evaluated the current source and preferred source of information as well as their online information seeking behaviours. A total of 411 patients with cancer were recruited from an ambulatory cancer centre. The patients’ physicians and healthcare specialists comprised a large majority of the patients’ information sources; they were also the most preferred source of information. 59.1% of the respondents used the Internet to search for cancer-related information, namely diagnosis and treatment options, side effects of treatment and complementary and alternative therapy; demonstrating the importance of the above information. Physicians (60.3%) and healthcare specialists (26.5%) were the largest and most preferred sources of information for cancer patients in our study. It was not uncommon for cancer patients to use the Internet to search for additional information demonstrating the need to integrate this tool more effectively for knowledge transfer for those patients who want it. It is important for healthcare professionals to help cancer patients by directing them to sources of quality information (including websites). In addition, the provision of guidelines on how to evaluate health information on the Internet would be helpful to cancer patients.