Introduction <p>Ventilator-associated pneumonia (VAP) is a prominent cause of morbidity and mortality in intensive care unit patients. Ceftolozane/tazobactam could be a cost-effective treatment option prior to culture test result for treatment of VAP. This study aims to evaluate the cost-effectiveness of ceftolozane/tazobactam compared to meropenem in Colombia.</p> Methods <p>We constructed a cost-effectiveness model using a short-term decision tree, to evaluate the cost-effectiveness of C/T for the treatment of patients VAB versus meropenem. The model was analyzed probabilistically, and a value of information (VOI) analysis was conducted to inform the value of conducting further research to reduce current uncertainties in the evidence base. Cost-effectiveness was evaluated at a willingness-to-pay (WTP) value of US$4,487.</p> Results <p>Meropenem has a lower cost of US$ 6042, while CT has a higher cost of US$ 6324, with an incremental cost of US$ 281 compared to Meropenem. In terms of effectiveness, the probability of cure (C/T = 72%, Meropenem = 85%). CT shows a slightly higher effectiveness with an incremental effectiveness of 1.0%. The incremental cost-effectiveness ratio (ICER) is calculated at <i>U</i>S$ 27,869 per cured patient. The base case results were robust to most of variations in utilities, transition probabilities, relative risk. The price threshold analysis for the cost for intravenous powder for injection of CT (1&#xa0;g) shows if the cost per injection es lower than US$36; that it a reduction of 32% in it cost, this alternative is cost-effective compared to meropenem.</p> Conclusion <p>Ceftolozane/tazobactam is not a cost-effective option compared to Meropenem to treat patients with VAP in Colombia. If the cost for intravenous powder for injection of Ceftolozane/tazobactam is reduced by 32%, this alternative could be cost effective respect to meropenem.</p>