Introduction: Human immunodeficiency virus (HIV) is predominantly transmitted through unprotected sexual intercourse. Condom use in long-term relations is uncertain, thus antiretroviral treatment can be the most efficient method of preventing HIV transmission. The objective of this study was to analyze epidemiological characteristics of HIV serodiscordant couples coming to consecutive visits. Material and methods:Data on demographics, HIV viral load, hepatitis B virus (HBV) and hepatitis C virus (HCV) co-infections of HIV positive individuals (index patients) and data on sexual behavior, condom use in sexual relations were obtained from medical files.Results: There were 52 couples investigated: 16 (31%) homosexual and 36 (69%) heterosexual ones. In general, 47 (90%) HIV positive patients were on combination antiretroviral therapy (cART) and 42 (89%) had HIV RNA below 50 copies/ml at last measurement. During one year of observation, 18 (35%) patients had detectable HIV RNA. Out of index patients, 18 (35%) were anti-HCV positive, 1 (2%) was HBSAg positive and 4 (7.7%) were VDRL positive. Twenty (38%) persons admitted to have unprotected sexual contacts, 6 (29%) homosexual men and 15 (71%) heterosexual persons. Only 29 (56%) HIV negative partners were tested regularly for HIV. Ten (19%) of HIV positive patients already had children. There were five pregnancies during the time of the study. Four couples declared a desire to have children. Only 3 couples considered assisted reproduction. Conclusions:Unprotected sex occurs often among serodiscordant couples observed. Thus regular cART should be emphasized. Frequent co-infections (HCV and syphilis) among index patients prove that it is necessary to test HIV negative partners for these infections. The observation confirms purposefulness of couple counseling about safe conception.