Introduction Fractional exhaled nitric oxide (FeNO) is a simple, noninvasive measurement of airway inflammation with minimal discomfort to the patient and with results available with a few minutes. This study aimed to evaluate the cost-effectiveness of the Fractional exhaled nitric oxide in asthma. Methods A markov model was used to estimate the cost-utility of FeNO versus standard treatment (control group) an infant with mild to moderate allergic asthma. Cost data were obtained from a retrospective study on asthma from tertiary center, in Medellin, Colombia, while utilities were collected from the literature. The analysis was carried out from a societal perspective. Results The model showed that FeNO, was associated with lower total cost than SC (US $1333 vs US $1452 average cost per patient), and higher QALYs (0.93 vs. 0.92 average per patient); showing dominance. The probability that MS provides a more cost-effective use of resources compared with standard therapy exceeds 99% for all willingness to pay thresholds Conclusion FeNO was cost-effective for the hospital treatment of an infant with infant with mild to moderate allergic asthma. Our study provides evidence that should be used by decision-makers to improve clinical practice guidelines and should be replicated to validate their results in other middle-income countries.