Chlamydia trachomatis ocular and urogenital infections represent major public health problems, whereas Chlamydophila pneumoniae is a common aetiological agent of community-acquired pneumonia. The obligate intracellular lifestyle of these established pathogens poses challenges to both their diagnosis and treatment. Tetracyclines, macrolides and quinolones remain the antimicrobials of choice for the treatment of infections due to Chlamydiaceae.