In collaboration with the Dutch Institute for Health Care Improvement (CBO) and on the basis of recent developments, new guidelines have been developed for the diagnosis and treatment of HIV-infected patients. The most important recommendations are: - Treatment of adult patients is indicated if HIV load > 30,000 RNA copies/ml, or when CD4+ cell count is 5,000 copies/ml, even when CD4+ cell count is > 500 x 106 cells/l. - Optimal antiretroviral treatment consists of a combination of two nucleoside reverse transcriptase inhibitors (NRTIs) and one protease inhibitor, or a combination of two NRTIs and one non-nucleoside reverse transcriptase inhibitor. - Patients on antiretroviral treatment should be monitored every 3 months. - Undetectable HIV load should be the target of first- or second-line antiretroviral treatment. - In order to prevent HIV transmission from mother to child, prescription of antiretroviral drugs after the first three months of pregnancy is indicated in pregnant women with a detectable HIV load. - Prophylaxis of opportunistic infections can be discontinued if CD4+ cell count recovers above 200 × 106/l. - In case of exposure to HIV due to a needle or other occupational accident or unsafe sexual contact, post-exposure prophylaxis should be offered after careful risk evaluation. - Preferably, vaccination to prevent pneumococci infections, influenza, hepatitis A or hepatitis B should be given when CD4+ cell count is > 200 x 106/l