AIMS: To examine perceived need for, and provision of, information prior to participation in a diabetes screening programme in English general practices. METHODS: Case studies using qualitative semi-structured interviews with patients and practitioners in five participating practices. RESULTS: Participating patients generally demonstrated a lack of understanding of issues in relation to the benefits and disadvantages of diabetes screening or the implications of screening test results. Posted invitation letters provided written information but did not necessarily ensure that patients were better informed than those invited by telephone or opportunistically when attending the practice for another reason. Not all patients interviewed wanted the extent of information that would be required to enable them to give fully informed consent to screening. CONCLUSIONS: The ways in which information is provided to patients requires careful consideration so that a patient has sufficient understanding to make a decision about undergoing a screening test and understands the implications of test results. There is a potential conflict between the ideal of fully informed choice and patient expectations that they can depend on professionals to make the appropriate decision on their behalf.