ABSTRACT: The diagnosis of urinary tract infection (UTI) can be difficult in elderly patients, who may present with vague complaints or atypical symptoms. Office-based urine testing is less sensitive and specific in these patients because they are less likely to have pyuria and more likely to have contaminated specimens than younger adults. Antibiotics used to treat uncomplicated UTIs in the elderly include trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolones, fosfomycin, nitrofurantoin, cephalosporins, carbenicillin, and trimethoprim. When you select an agent, consider the side-effect profile, cost, bacterial resistance, likelihood of compliance, and the patient's renal function. The optimal duration of treatment of uncomplicated UTIs in elderly women is still a matter of debate. Options for prophylaxis in patients who have recurrent uncomplicated UTIs include estrogen replacement therapy (vaginal or oral) and nitrofurantoin.