The aim of the present study was to correlate statements made by 100 patients of an internal medicine ward regarding their compliance before hospitalization, with their personal knowledge of an convictions about their own pharmacotherapy. Data were collected in structured interviews of 9 questions carried out by a medical person not involved in current treatment. The patient sample (mean age +/- SE: 6.8 +/- 1.3 years) included 42 women and 58 men whose mean number of prescribed medications before hospitalization was 4.7 +/- o.22. Good treatment compliance was reported by 78% of the patients, while 13% admitted non- compliance. Knowledge about the drugs they had been prescribed ranged from perfect (30%) to none (34%) and was significantly different between compliers and non-compliers, with patients who know their medications at least by name being fairly compliant (p = 0.048). Independently of the statement about compliance, the patients used three main strategies to ensure regular intake of daily medication: visual aids (69%), coupling to a ritual (26%) or supervision by a third person (6%). Criteria such as gender, the number of prescribed medications, personal perseverance, or personal definition of the sense of the prescribed pharmacotherapy, or the arguments expected to be used by a physician when recommending a pharmacotherapy did not differ between compliers and non-compliers. Thus, compliance appears to have its roots mainly in the conviction level of each patient : intention will be transformed into action when deemed correct according to the individual's personal criteria. This may lead to both compliance and to non-compliance with medical recommendations. This study, which is based on patient reports, supports the conclusion that drug compliance may be enhanced by increasing patient's knowledge about their own pharmacotherapy and by having patients use specific strategies to guarantee regular daily intake of drugs. Prospective studies should therefore address the question of whether providing specific information according to a patient's convictions will untimately translate into improved compliance.