Introduction/Objective. Patients with AS often experience chronic musculoskeletal pain, fatigue and stiffness, which may contribute to psychological distress and sexual dysfunction. This study aims to assess prevalence of ED in patients with AS and identify potential associations between clinical parameters related to AS with the presence of ED. Methods. Forty consecutive male patients with the AS (mean age 42.8 ? 8.9 years) and 60 healthy men (mean age 38.9 ? 10.9 years) were included. All subjects filled-in the International Index of Erectile Function (IIEF) questionnaire, as well as the Beck anxiety inventory (BAI) and the Beck depression inventory (BDI). In patients with AS disease activity was evaluated using the Ankylosing Spondylitis Disease Activity Score (ASDAS) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), functionality using the Bath Ankylosing Spondylitis Functional Index (BASFI), and quality of life using the Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire. Results. ED was significantly more frequent in patients with AS compared to controls (52.5%: 25%, p = 0.049). AS patients with ED had more severe symptoms of depression, than AS patients without ED (p = 0.034). Ac-cording to ASQoL scores, patients with AS and ED had a worse quality of life, compared to patients with AS without ED (p = 0.022). The increase in one unit of ASQoL increased the odds of having ED for 17.5% (p = 0.035). Conclusion. ASQoL score, as a measure of quality of life, was the only independently associated parameter with the presence of ED. It is necessary to raise awareness of ED in patients with AS.