OBJECTIVE: To describe what patients want to know about their medications and how they currently access information. To describe how physicians and pharmacists respond to patients' information needs. To use patients', physicians', and pharmacists' feedback to develop evidence-based treatment information sheets. DESIGN: Qualitative study using focus groups and a grounded-theory approach. SETTING: Three regions of Canada (British Columbia, Nova Scotia, and Ontario). PARTICIPANTS: Eighty-eight patients, 27 physicians, and 35 pharmacists each took part in one of 19 focus groups. METHOD: Purposeful and convenience sampling was used. A trained facilitator used a semistructured interview guide to conduct the focus groups. Analysis was completed by at least two research-team members. MAIN FINDINGS: Patients wanted both general and specific information when considering medication treatments. They wanted basic information about the medical condition being treated and specific information about side effects, duration of treatment, and range of available treatment options. Physicians and pharmacists questioned the amount of side-effect and safety information patients wanted and thought that too much information might deter patients from taking their medications. Patients, physicians, and pharmacists supported the use of evidence-based treatment information sheets. CONCLUSION: Patients and clinicians each appear to have a different understanding of what and how much information patients should receive about medications. Feedback from patients can be used to develop patient-oriented treatment information.