Doxycycline is used to treat bacterial infections. Doxycycline is in a class of medications called tetracycline antibiotics. In addition to the general indications for all members of the tetracycline antibiotics group, doxycycline is frequently used to treat chronic prostatitis and pelvic inflammatory disease. Especially intracellular agents, such as chlamydia, are generally susceptible to doxycycline. Assuming this infection to be responsible for the chronic bladder pain syndrome in women, therapy will be performed in accordance with the authorised indication and dosage.Bacterial cystitis is an exclusion criterion for the diagnosis of chronic bladder pain syndrome. However, the detection of microorganisms such as Chlamydia trachomatis, Ureaplasma urealyticum and Mycoplasma genitalium remains a challenge so that these organisms may well be involved in the pathogenesis of chronic bladder pain syndrome. This is supported by the findings of our retrospective study1 that doxycycline orally for 4 weeks including therapy of the sexual partner lead to a reduction of symptoms in 71% of women complaining of persistent urgency and frequency, chronic urethral and/or bladder pain. Therefore, doxycycline therapy is sensible, especially considering that there are only a few, costly and often little effective symptomatic other treatment options.