To evaluate the hospitalization rates in 2 pre–prostate biopsy antibiotic protocols.Two prebiopsy protocols were compared. CiproAlone required ciprofloxacin 500 mg twice daily starting 1 day before biopsy and continuing for 3 days after biopsy (4 days total). Diabetic patients were prescribed ciprofloxacin for 4 days after biopsy. CiproCeft required 1 dose of oral ciprofloxacin 500 mg 1 hour before the biopsy and ceftriaxone 1 g intramuscular at the time of the biopsy. Hospitalization rates between the CiproAlone vs CiproCeft protocols were examined.A total of 4134 biopsies were identified—2093 in the CiproAlone cohort and 2041 in the CiproCeft cohort. The post–prostate biopsy infection hospitalization rate was 0.6% (14 patients) in the CiproAlone group vs 0.0% (0 patients) in the CiproCeft group (P <.0001). Of the patients hospitalized, 12 fit systemic inflammatory response syndrome (SIRS) criteria. Eight of 14 hospitalized patients fit the sepsis (SIRS and source of infection) criteria. Positive cultures (urine and/or blood) resulted from 71% (n = 10) of hospitalized patients. Antibiotic resistance was analyzed. Diabetes mellitus was associated with hospitalization after prostate biopsy (P = .01) in our population, but there was no difference between the 2 groups in the rates of diabetes mellitus (P = .46). Patient age, prostate-specific antigen level, number of biopsy cores obtained, race, and previous antibiotics exposure were not found to be independent predictors of post–transrectal ultrasonography biopsy hospitalization for infection using a multivariate regression analysis.A prophylactic prebiopsy protocol including 2 classes of antibiotics, single-dose ciprofloxacin, and singe-dose intramuscular ceftriaxone reduced post–transrectal ultrasonography biopsy rates of hospitalizations compared to oral ciprofloxacin alone.