INTRODUCTION From 1985 until the end of 2012 16,314 cases of HIV infection, 2,848 AIDS cases and 1,185 deaths of AIDS patients were registered in Poland. OBJECTIVE To analyze the epidemiological situation of newly diagnosed HIV infections and AIDS cases in Poland in 2011. MATERIALS AND METHODS Descriptive analysis of newly detected HIV cases and incident AIDS cases was performed based on routine notifications by clinicians and laboratories. Data on the number of HIV tests from annual survey among laboratories were also used. RESULTS In 2011 there were 1,105 HIV cases diagnosed in Poland (detection rate 2.87 per 100,000 population), including 23 among non-Polish citizens. The total number of AIDS cases was 175 (incidence 0.45 per 100,000) and 65 AIDS patients died. Compared to 2010, there was an increase in infections diagnosed among men who have sex with men (MSM) (from 51.9% to 67.1% of cases with known transmission mode). HIV infection is mainly detected among people aged 20 to 39 years (69.9%) and among males (82.2%). The percentage of late presenters (defined by the time between HIV and AIDS diagnoses of less than 3 months) remained at the same level as in 2010 (9.2% of newly diagnosed HIV infections). CONCLUSIONS Assessment of epidemiological situation is limited by the missing data on the probable transmission route in a large percentage of reports of newly diagnosed HIV cases. The significant increase of HIV infections among MSM call for strengthened prevention measures in this group.