OBJECTIVES: 1) To assess the willingness of patients to provide information about medical treatment, and 2) to practically demonstrate that useful information can be collected METHODS: Public acceptability towards reporting side-effects and efficacy of medical treatments was assessed by 1) online questionnaire, and 2) assisted questionnaire.  Results from the first 137 respondents to the on-line questionnaire and 115 respondents to the assisted questionnaire are reported. A total of 110 leaflets were distributed inviting patients to log on to a dedicated website and provide information on post-vaccination symptoms.  Information was gathered on the day of vaccination, two days later and at day eight.  RESULTS: A total of 94% of interviewees were aware of the possibility of side effects. Of interviewees who had personal experience of side effects, 39% did not report them.  The perceived principle conduit (81%) for reporting was to the physician.  The motivating factors for reporting adverse drug reactions (ADR’s) in order of frequency was stated to be, ensuring medical safety of others (31%), ensuring their own future good health (28%) the advice of pharmacists/nurses (12%) and financial incentives if available (7%).  A total of 73% reported willingness to report side-effects via the Internet.  A total of 110 leaflets were distributed at an influenza vaccine clinic inviting patients to log on to an interactive website and provide information. 73 (66%) registered on the day of vaccination, 70 (96%) responded at day two and 66 (90%) at day eight.  Statistics on pain and discomfort demonstrate that while the majority of patients have no pain, 8% experienced significant discomfort and 3% pain for greater than one hour.  Of side effects reported, none required medical attention and the majority were self-limiting. CONCLUSIONS: We have confirmed that patients are willing to provide information about medical treatment via an interactive web-based system.  This technique has potential for the conduct of naturalistic studies and for post-marketing surveillance.