There is no satisfactory treatment for obstructive sleep apnoea (OSA). Supplemental low-flow oxygen therapy (LFO2) has been shown to reduce hypoxaemia and is well tolerated by patients with OSA. However, oxygen therapy may be beneficial only to certain subsets of patients with OSA. In this study, we evaluated a 10-min awake ventilatory chemoreflex test in predicting individual OSA response to 2 months of LFO2 therapy.At baseline, patients with OSA underwent ventilatory chemoreflex testing in the afternoon, prior to the overnight polysomnography. Subjects were reassessed with polysomnography after 2 months of nocturnal oxygen treatment.20 patients with OSA completed the study. After 2 months of O2 treatment, changes in the apnoea-hypopnoea index (AHI) were significantly correlated with baseline CO2 ventilatory response threshold (VRT) and chemosensitivity (p<0.05). In predicting a fall in AHI, the area under the receiver operating characteristic curve (AUC) was 0.79 for VRT and 0.89 for chemosensitivity. When these two variables were combined in a logistic regression model, the prediction effect became stronger with an AUC of 0.97, sensitivity of 0.92 and specificity of 0.83.Our awake ventilatory chemoreflex test could be considered a simple potential clinical tool to predict individual OSA response to oxygen therapy. It could provide a novel personalised medicine approach to OSA treatment.