Recent studies have shown that in selected conditions antiretroviral drugs can be used to protect HIV seronegative persons from becoming infected, when exposed to the risk of sexual HIV transmission. This concept of 'pre-exposure prophylaxis' or 'PrEP' has raised many questions that concern cost, safety and ethical issues. In this article, different aspects of PrEP are analysed with a view to trying to answer the question whether today's society is already prepared to accept PrEP as one of the tools to prevent transmission of HIV by high-risk sexual contacts.