Context:Pulse oximetry has become mobile with the use of smartphone and Bluetooth wireless technology. This technology offers many benefits but has not been extensively studied. There is a need to further validate its clinimetric properties for health professionals to provide proper guidance to patients.Objective:This investigation assessed the concurrent validity of the iSpO2pulse oximeter against a traditional pulse oximeter in measuring short-term resting blood oxygen saturation (SpO2) and pulse rate.Design:Observational study of reliability.Setting:University kinesiology laboratory.Participants:Thirty healthy, recre-ationally active adults (18 men, 12 women; mean age = 25.7 ± 5.46 years, mean height = 170.3cm ± 9.51, mean body mass = 76.4 kg ± 19.33).Intervention:Resting measurement of SpO2and pulse rate using the iSpO2pulse oximeter with the iPad Mini and a traditional pulse oximeter with Bluetooth.Main Outcome Measure:Resting SpO2and pulse rate were concurrently measured over 5 min.Results:The concurrent validity between the iSpO2and traditional pulse oximeter was moderate for measuring SpO2, intraclass correlation coeffcient (ICC)(3, 1) = .73,SEM= 0.70%, and good for pulse rate, ICC(3, 1) = .97,SEM= 1.74 beats per minute (bpm). The minimal detectable change at the 95% confidence interval for both instruments suggests that there may be 1.94% disagreement for SpO2and 4.82 bpm disagreement between pulse oximetry methods. The 95% limits of agreement (LoA) for measuring SpO2suggests that the iSpO2and traditional pulse oximeters may vary -0.28 ± 1.98%, or approximately 2%. The 95% LoA for measuring pulse rate suggests that the iSpO2and traditional pulse oximeter may vary 1.74 ± 4.98 bpm, potentially upward of 6 bpm. On the basis of the results of the LoA, it appears that there may be a slight systematic bias between the two devices, with the traditional pulse oximeter producing higher pulse rates than the iSpO2.Conclusion:The findings suggest that both instruments may be beneficial for indirect short-term measurements of resting SpO2and pulse rate.