To assess the accuracy of the RIP based CHIME home monitor (NIMS, Inc., Miami FL) in identifying potentially obstructed breaths recorded during an apnea, waveforms identified as obstructed breaths (OB) were evaluated on simultaneously obtained polysomnography (PSG) recordings. An OB was defined from the CHIME monitor RIP channels as a sum channel deflection <25% of the preceding baseline and out-of-phase deflections on the rib cage and abdominal channels. Based on independent review of the PSG, each potentially OB was categorized as either “obstructed”(amplitude of carbon dioxide and thermistor waveforms both <25% of preceding baseline), “not obstructed”(amplitude of carbon dioxide and thermistor waveforms >75% and >25%, respectively), or “uninterpretable”(inconsistent carbon dioxide and thermistor waveforms). PSG and CHIME recordings ≥8 hrs in duration were obtained from 506 infants of whom 10 met inclusion criteria of ≥5 potentially OB during a ≥16 sec apnea, based on manual scoring (41 total apnea events, duration 16-63). Eighty nine potentially OB were randomly selected from a total of 171 to prevent over representation of any one infant. Among the 89 potentially OB evaluated, 69 (77.5%; 95% CI 69, 86) were judged“obstructed”, 4 (4.5%; 95% CI 0.2, 9) “unobstructed”, and 16 (18%; 95% CI 12, 26) “uninterpretable”. Calculation of 95% CI accounted for multiple observations on each subject. Although these data do not allow an estimate of the frequency that the CHIME monitor failed to identify obstructed breaths, they provide a level of confidence that when CHIME monitor scoring identifies multiple potentially OB associated with apnea≥ 16 sec, these do represent obstructed breaths based on end tidal carbon dioxide and nasal/oral thermistor criteria.