OBJECTIVES: Determine the cost-effectiveness of three carbapenemic anti-infectives (imipenem, meropenem and doripenem) for treatment of VAP in Colombia. METHODS: A decision analysis model was built based on efficacy measures obtained from published clinical trials. Local direct costs were estimated from a payer perspective using 2009 listed rates of drugs, general ward daily stay and intensive care daily stay (with and without mechanical ventilation). The used exchange rate was Col$1968 per US$ (January 2010). The time horizon was defined as a “censored discharge” (first to happen among death, discharge or stay until day 35 after therapy finishing). Effectiveness was measured in terms of clinical cure rates. A multivariate probabilistic sensitivity analysis was done through 1000 Monte Carlo simulations. An additional model was run including costs associated to the risk of pseudomona transmission. These costs were estimated through a Markov model based on the daily probability of transmission from an initial pseudomona-free state to contaminated or infected states with sensitive and resistant pseudomona strains. RESULTS: Average VAP direct costs were US$ 9,912 for imipenem, US$ 10,196 for meropenem and US$ 9,020 for doripenem. Costs differences were mainly related to differences in the ICU stay, particularly time on mechanical ventilation (13, 13 and 10 days, respectively). Psudomona transmission-related costs were US$ 333; US$ 332 and US$ 191, respectively. Monte Carlo analyses showed that doripenem was more cost-effective than meropenem and imipenem in 95% and 91% of samples, respectively. Additionally, doripenem was dominant over meropenem and imipenem in 46% and 44% of samples, respectively. CONCLUSIONS: Initial treatment of VAP cases with doripenem is the most cost-effective alternative compared to other carbapenems as imipenem and meropenem. This advantage is related to its effect diminishing the intensive care unit stay due to a reduction in time on mechanical ventilation.