Ventilator-associated pneumonia (VAP) remains a significant challenge in critical care. We conducted a secondary analysis of a multicenter, prospective, randomized trial comparing levofloxacin (750 mg iv q24h) with imipenem-cilastatin (500-1000 mg iv q6-8h) for treatment of nosocomial pneumonia and focused on the subgroup of patients with VAP. The study cohort included 222 patients, with half (111) of the patients assigned to each treatment group. The patients in both groups were similar with respect to age, severity of illness, and duration of mechanical ventilation before the onset of VAP. Among the intention-to-treat population, clinical success was achieved in 58.6% of patients receiving levofloxacin, compared with 63.1% of patients receiving imipenem-cilastatin (P = .49; 95% confidence interval for the difference, -8.77% to 17.79%). Microbiological success and 28-day mortality rates were also comparable. Multivariate analysis demonstrated that assignment to antibiotic treatment (i.e., levofloxacin vs. imipenem-cilastatin) was not predictive of outcomes, thus suggesting that the treatment regimens were equivalent. Both levofloxacin and imipenem-cilastatin regimens were well tolerated and had similar adverse event profiles.