The care management of patients treated for cases of sexual or blood exposure requires stringent clinical and biological follow-up procedures. Despite the provision of information about the importance of regular follow-up, the number of patients dropping out of screening consultations at the Hospital Lariboisière-Fernand Widal (Assistance Publique-Hôpitaux de Paris) has increased. The main purpose of this study is to improve follow-up for patients treated with anti-retroviral prophylaxis following a known sexual or blood exposure. An investigation based on 5 markers of a targeted clinical audit form ("drop-outs" or lost to follow-up, conduct of HIV serology tests, traceability of clinical, biological and compliance monitoring) was carried out. A review of practices was conducted on the basis of an analysis of patient cases over a six-month period, followed by the implementation and evaluation of corrective measures over a two-year period. A significant decline in the number of patients lost to follow-up was observed. The study shows a significant improvement in other markers: serological follow-up, compliance traceability, and clinical and biological monitoring. These results were observed between 2005 and 2007. Two distinctive effects were identified: improvement in patient care management and the quality of care, and the empowerment of actors, thereby ensuring a certain continuity of action. The decline in the rate of lost to follow-up patients and improved monitoring of compliance and iatrogenic risks confirm these effects. The overall approach is incorporated into an evaluation of professional practices.