Acute uncomplicated cystitis (AUC) is one of the most common bacterial urinary tract infections. AUC frequently occurs in young sexually active, as well as postmenopausal, women. According to the guidelines published by the Infectious Diseases Society of America in 1999, the standard antimicrobial regimen for treatment of AUC is 3 days with trimethoprim-sulfamethoxazole (TMP/SMX); however, today the most popular antibiotics are the fluoroquinolones because of the emergence of uropathogens that are resistant to TMP/SMX. Fluoroquinolone resistance is also increasing worldwide, although the resistance rates have not been as high as those for TMP/SMX. Extended-spectrum beta-lactamase (ESBL)-producing strains are another problem because most nosocomial ESBL producers are also resistant to non-beta-lactams, such as the fluoroquinolones. Under such circumstances, 3 days of therapy with fluoroquinolones or 7 days with beta-lactams is recommended for empirical therapy, although these regimens should be re-evaluated in the next decade. Low-dose fluoroquinolones should no longer be used because of the potential for emergence of resistance.