PURPOSE: The conventional primary therapy for chronic bacterial prostatitis (CBP) is the use of antibiotics. However, the therapy has a low cure rate and long-term use of antibiotics can lead to adverse effects including bacterial resistance. For these reasons, a new therapy for CBP is strongly needed. MATERIALS AND METHODS: To evaluate the anti-inflammatory and antimicrobial effects of selenium-rich hot spring water on CBP, rats were divided into four groups and treatment was administered for four weeks as follows: (1) control (n=8), (2) ciprofloxacin (n=8), (3) selenium-rich hot spring water (n=8), and (4) selenium-rich hot spring water with ciprofloxacin (n=8). Drip infusion of bacterial suspension (E. coli Z17 O2:K1;H-) into Spargue-Dowley rats was then conducted to induce CBP. Four weeks later, the results of prostate tissue and urine culture and histological analysis on the prostate were analyzed in each group. RESULTS: The use of ciprofloxacin, and selenium-rich hot spring water with ciprofloxacin showed statistically significant decreases in bacterial growth and improvements in prostatic inflammation compared with the control group (p<0.05). The selenium-rich hot spring water with ciprofloxacin group showed a statistically significantly lower rate of bacterial growth and and greater improvements in prostatic inflammation than the ciprofloxacin group (p<0.05). CONCLUSIONS: These results suggest that spring water may be an effective material in the treatment of CBP. Notably, the combination treatment of selenium-rich hot spring water and ciprofloxacin has synergistic effects. Therefore, we can suggest that the combination of selenium-rich hot spring water and ciprofloxacin may be effective in the treatment of CBP, and with a higher success rate than ciprofloxacin alone.