Empirical antibiotic therapy is the preferred primary treatment modality for chronic bacterial prostatitis (CBP). However, this method of treatment has a low success rate and long-term therapy may result in complications and the appearance of resistant strains. Therefore a new alternative method for the prevention of CBP is necessary. There are several reports that ginsenoid has a preventive effect on urinary tract infection (UTI). To evaluate the preventive effect of ginsenoid on CBP compared to conventional antibiotics, we carried out an experiment in a rat model of the disease. Four groups of adult male Wistar rats were treated with the following medications: (1) control (no medication), (2) ciprofloxacin, (3) ginsenoid, and (4) ciprofloxacin/ginsenoid. All medications were given for 4 weeks, and then we created a CBP model in the animals by injecting an Escherichia coli Z17 (O2:K1;H(-)) suspension into the prostatic urethra. After 4 weeks, results of microbiological cultures of prostate and urine samples, as well as histological findings of the prostate in each group were analyzed. The microbiological cultures of the prostate samples demonstrated reduced bacterial growth in all experimental groups compared with the control group. Histopathological examination showed a significantly decreased rate of infiltration of inflammatory cells into prostatic tissue and decreased interstitial fibrosis in the ginsenoid group compared with the control group. Inhibition of prostate infection was greater in the group receiving both ginsenoid and antibiotic than in the single-medication groups. Although the findings of this study suggest a preventive effect of ginsenoid, preventive methods for CBP are still controversial.