A 69-year-old man with diabetes mellitus was diagnosed with a prostate abscess. Although the pathogen was fluoroquinolone-resistant Escherichia coli and the oral administration of trimethoprim-sulfamethoxazole was initiated, the infection recurred after three months. The antibiotic therapy was subsequently changed to intravenous fosfomycin, and the patient's condition promptly improved. Four weeks of fosfomycin therapy was successfully continued without any adverse events. In the era of antibiotic resistance, revival of forgotten drugs is an important issue for clinicians. Fosfomycin can be applied as an alternative option for prostate infections, considering the remaining susceptibility of multidrug-resistant pathogens to fosfomycin and the good pharmacokinetics of this drug in prostatic tissue.