"Purpose: Proper guidelines concerning antibiotic administration for acute bacterial prostatitis (ABP) are unclear. We retrospectively analyzed treatment status and clinical outcomes to establish a proper treatment guideline. Materials and Methods: The clinical records of 669 patients from 21 hospitals diagnosed with ABP were reviewed. Prior manipulation, antibiotics administration, mean length of treatment, complication and procedure were analyzed. Results: The mean age of 538 patients (80.4%) without manipulation (group 1) and 131 patients (19.6%) with manipulation (group 2) was 58.3 years (range 19-88 years). Transrectal prostate biopsy was the most common cause of acute bacterial prostatitis (n=66; 50.4%). Of the clinical symptoms in the non-manipulation and manipulation groups, fever was most common (88.2% and 86.3%, respectively). Acute urinary retention (14.3% and 28.1%, respectively) was significantly increased in the manipulation group (p<0.05). Escherichia coli was the most frequently isolated bacterium from urine (72.0% and 66.7% of cases, respectively). Mean length of treatment was 6.5days and 7.9days, respectively; the difference was significant (p<0.05). Combination antibiotic therapy with third generation cephalosporin+aminoglycoside was used in 49.3% and 55.5% of cases, respectively. For single antibiotic therapy, second generation quinolones were used the most (35.5% and 34.3%, respectively). Sequale occurred in 29 group 1 patients (5.4%) and 20 group 2 patients (15.3%); the difference was significant (p<0.05). Conclusions: Prior manipulation was associated with 20% of ABP patients. Regardless of manipulation, clinical outcome was similar after treating with appropriate antibiotics."