Urinary tract infections (UTIs) are the most common bacterial infections treated in the outpatient setting and range in severity from minimally symptomatic cystitis to severe septic shock in a wide array of patients. Diagnosis of uncomplicated cystitis can be inferred from history and physical, and confirmed by urinalysis. Appropriate antimicrobial therapy should rapidly improve symptoms in all UTIs. Treatment can be further tailored according to severity of illness, analysis of individualized risk factors, and antimicrobial resistance patterns. This article discusses treatment options in light of bacterial resistance in the twenty-first century.