Thirty-seven patients receiving antiretroviral therapy were interviewed in depth in preparation for a quantitative study of patients' perceptions of their treatment. Patients described three types of difficulty with treatment: conflict between treatment recommendations and daily life, side effects (immediate and long term) and fear that treatment would reveal their seropositivity. These problems interfered with treatment adherence which was otherwise generally good. The problems are rarely evoked during medical consultations: certain patients think they are not pertinent, and physicians give priority to clinical and laboratory examinations. Training must be carried out in order to permit physicians to raise all the factors (including psychosocial factors) that are liable to reduce the quality of treatment adherence.