Fractional exhaled nitric oxide (FeNO) testing is a simple, safe, non-invasive test which is suitable for use in primary care provided it is carried out by a competent clinician who can interpret the results. Raised FeNO levels can only be found when type-2 airway inflammation is present (Wang et al, 2023). FeNO testing is currently regarded as an optional test to identify eosinophilic asthma for those with an intermediate probability of asthma. The question is, could FeNO testing lead to a more personalised approach for the management of airways diseases? This article discusses the current recommendations, the relevance of FeNO testing, along with the limitations and ways to utilise FeNO testing in a primary care setting.