Background: Poly(somno)graphy (P(S)G) is the gold standard for the scoring of residual respiratory events during continuous positive airway pressure (CPAP). Studies comparing the P(S)G scoring with the automatic scoring by the in-built software of CPAP devices have reported acceptable agreements except for the hypopnea index (HI). Aims and objectives: To compare the automatic scoring by the software of the CPAP device and manual scoring using the software tracings of the CPAP device integrating pulse oximetry (SpO2) with an in-lab PG.Methods: Consecutive clinically stable children treated with constant CPAP (ResMed) for at least 1 month and scheduled for a nocturnal PG were recruited. A pulse oximeter was connected to the CPAP device. The PG apnea-hypopnea index (AHIPG), scored according to the AASM guidelines, was compared to the automatic AHI reported by the CPAP device (AHIA CPAP) and the manual scoring of the AHI on the CPAP software (AHIM CPAP).Results: Fifteen children (1.5-18.6 years) were included. Mean residual AHIPG was 0.9±1.2/h (0.0-4.6/h) vs. AHIA CPAP of 3.6±3.6/h (0.5-14.7/h) (p<0.001), and AHIM CPAP of 1.2±1.6/h (0.0-5.1/h) (p=0.01). Correlation between AHIPG and AHIA CPAP was good (r=0.667; p=0.007), and improved when considering AHIM CPAP (r=0.933; p<0.001). Strong correlations were also observed between the PG apnea index (AI) and HI and the manually scored AI and HI on CPAP, respectively.Conclusions: Manual scoring of respiratory events on the in-built software tracings of CPAP devices integrating SpO2 signal is promising. These results have to be confirmed in patients with higher AHI.