At the heart of the healthcare system, physicians and pharmacists have always played essential and complementary roles. However, their roles have evolved over time in response to the emergence or resurgence of certain diseases, clinical and medical advances, economic constraints, legislative frameworks, and public health priorities. Since the emergence of AIDS, general practitioners have played a leading role in preventing risky sexual behavior, conducting HIV testing, and caring for people who are HIV-positive or have AIDS. Over time, their practices have changed significantly, with current guidelines now requiring comprehensive patient care. Alongside the physician, the pharmacist has also seen their role evolve. Today, the pharmacist’s advice goes beyond strictly providing information on the proper use of medications and adherence to prescriptions. Their code of ethics obliges them to contribute to the protection of public health. Prevention is an integral part of their duties, particularly in the areas of contraception and the prevention of sexually transmitted infections. In the 2003 Doctors/Pharmacists Health Barometer, the involvement of general practitioners and pharmacists in prevention and patient support regarding contraception and sexually transmitted infections (STIs) was assessed across the three levels of prevention. Primary prevention was addressed through general practitioners’ promotion of condom use, currently the only effective defense against sexually transmitted infections. Regarding pharmacists, the Health Barometer examined their role in HIV/AIDS prevention and their practices when dispensing oral contraceptives, including emergency contraceptives. In the context of secondary prevention, the focus is on general practitioners’ activities related to the surveillance and diagnosis of STIs. These activities concern the three main bacterial STIs (gonorrhea, chlamydia, syphilis) and one viral STI (HIV). As for tertiary prevention, it is addressed through the care and follow-up of HIV-positive individuals provided by both general practitioners and community pharmacists.[chapter excerpt]