Introduction. The infection with human immunodeficiency virus (HIV) is a contagious, human-specific disease. The virus progressively destroys host defense mechanisms and determines, after a variable period of time, acquired immunodeficiency syndrome (AIDS). The evolution is lethal, so far there is no curative etiological treatment. Worldwide, by 2017 year, there were 36.9 million cases of HIV infections, 17.5 million were women and 2.3 million were children under 15 years old. Currently, after more than 35 years, more than 30 million people have died from HIV infection worldwide Aim of the study. To analyze epidemiological characteristics, etiopathogeny, diagnostic methods and treatment principles of HIVinfection/AIDS. Materials and methods. Analysis of clinical material collected from the observation sheets of 50 patients hospitalized in Antiretroviral treatment unit of Dermatology and Communicable Diseases Hospital according to the following criteria: incidence, clinical signs and treatment of patients with HIV infection. Results. From a total of 50 patients, the highest incidence is for men, 60%, compared to 40% for women. Also, according to the age criteria, most patients were aged between 41-50 years (32%) and 31-40 years (28%). In Republic of Moldova, the most common route of contamination with HIV infection is the sexual way (34%). There is a decrease for the number of patients infected by the use of injectable drugs, compared to the last years of the last century, however this remains to have a large share (22%). A number of patients received an association of 2 or even 3 antiretroviral preparations simultaneously like: Nevirapine + Zidovudine + Lamivudine. Conclusions. 1. HIV infection is one of the most widespread infections, being responsible for the death of over 25 million people, in the last 30 years, through AIDS, the final phase, complicated with various infections. 2. Human immunodeficiency virus (HIV) targets the immune system and weakens the body's defense and surveillance mechanisms against infections, as well as against certain types of cancer. The virus damages the function of immune cells and destroys them, and the infected people gradually become immunodeficient. 3. HIV can be suppressed by antiretroviral therapy (ART), combinations that include two, three or more antiretroviral drugs (ARV). ARVT does not cure HIV infection, but prevents viral replication in the body of an infected person, helps the immune system to recover and fight against other infections.