Inclusion Criteria:- Non-pregnant, non-lactating women between the ages of 18 and 65 years with signs and symptoms of acute, uncomplicated, symptomatic lower UTI were eligible for enrolment. Dysuria and at least 1 clinical sign or symptom of a lower UTI (frequency, urgency, suprapubic pain, or gross hematuria) had to be present, with symptom onset </= 72 hours before study entry. - In addition, 1 pretreatment clean-catch MSU culture had to be positive for 1 to 2 urinary pathogens (>/= 10.000 colony-forming units {CFU}/mL). Women of childbearing potential were required to use 2 reliable methods of contraception during exposure to study drug. Exclusion Criteria:- Men- Women who were pregnant, nursing, or not using 2 medically accepted, effective methods of birth control- Known or suspected hypersensitivity to ciprofloxacin or the quinolone class of antimicrobials- Subjects taking urinary analgesic medication (phenazopyridine-containing products {eg, Pyridium}) within 24 hours before first dose of study drug and throughout the study for urinary tract pain- Subjects taking other analgesic medications (eg, nonsteroidal anti-inflammatory drugs [NSAID], acetaminophen-containing products, etc) for urinary tract pain or any other pain (eg, headache, back pain, joint pain, dental pain, sore muscles, etc) within 2 dosing intervals for that medication before first dose of study drug and throughout the study. More specifically, a subject who had taken a medication for pain could not be entered into the study until the time elapsed since her last dose of the medication was equal to at least 2 dosing intervals for that medication.- History of gastrointestinal illness that could interfere with absorption of orally administered antimicrobials- Subjects requiring concomitant administration of multivalent cation-containing products such as magnesium/aluminum antacids, sucralfate, Videx (didanosine) chewable/buffered tablets or pediatric powder, or products containing calcium, iron, or zinc, such as multivitamin preparations. These medications were not to be taken less than 6 hours before or 2 hours after study drug administration. - Subjects experiencing vaginitis- Subjects with a temperature >/= 38.3°C or >/= 101°F, flank pain, chills, or any other manifestations suggestive of upper UTI - Subjects with evidence of factors predisposing to the development of UTIs, including calculi, stricture, primary renal disease (eg, polycystic renal disease), or neurogenic bladder - Subjects currently taking, or who might require, antibiotics other than Cipro XR during the study period- Subjects who had received any systemic antibiotic therapy in the previous 48 hours, for any reason- Subjects who, in the opinion of the investigator, were unsuitable for enrollment and were unlikely to complete the course of treatment or to be available for follow-up- Subjects unable or unwilling to comply with the use of an electronic subject diary to record UTI symptoms and impairment of normal daily activities- Subjects requiring concomitant administration of theophylline - Inability to take oral medication for any reason - Subjects with >/= 3 episodes of UTIs in the past 12 months - Subjects with onset of symptoms more than 72 hours prior to study entry - Subjects with symptoms of a UTI within the 4 weeks prior to the present episode - Subjects with previous history of tendinopathy associated with fluoroquinolones - Subjects diagnosed with a rapidly fatal underlying disease (death expected within 6 months) - Subjects previously enrolled in this clinical study - Subjects with known neutrophil count < 1000/mm3, CD4 < 200/mm3, or other conditions associated with significant depression of host defense; HIV testing was not mandatory - Subjects taking an investigational drug in the last 30 days - Subjects who could not begin answering the first visit baseline questionnaire by 5:00 pm