Fluoroquinolones are recommended in the therapy of chronic prostatitis. Chlamydia trachomatis is one of the possible aetiological agents of chronic prostatitis. However, little is known about chlamydia survival in the presence of fluoroquinolones in patients with chronic prostatitis syndrome. For the first time, chlamydia survival in vitro in the presence of lomefloxacin (LOMX) (mostly recommended in the treatment of chronic prostatitis) versus levofloxacin (LVFX) (recommended in the therapy against chlamydia infection) is examined and analysed in the 33 chlamydia-infected patients with chronic prostatitis syndrome in this study. Antichlamydial activity in vitro of LOMX in patients with C. trachomatis and prostatitis was found to be more effective than LVFX. However, further clinical trials for these agents are recommended.