Noninvasive methods of monitoring are crucial in the management of intensive care patients, especially in the pediatric field. Pulse oxymetry measures arterial oxygen saturation in severely ill patients, allows oxygen requirements to be adjusted to the patient, reduces invasive gasometric studies and achieves continuous monitoring of the critically ill child. Motion and deficient tissular perfusion reduce the accuracy of the measured values, but more sophisticated pulse oximeters are more effective in preventing these artifacts. Capnometers are an excellent method of measuring end-tidal CO2 values in real time in intubated patients. Capnography produces a graphic curve of end-tidal CO2 while capnometry provides a numerical representation of this concentration. This technique is highly useful in the continuous monitoring of various respiratory problems and situations such as weaning or checking the correct placement of endotracheal cannulas.