Magnetic resonance imaging (MRI) has presented to anesthesiologists as unique challenge in patient monitoring because of its construction and principles of operation. Ferromagnetic materials within or near the scanner can distort the magnetic field, and monitoring wires act as antennae and this may result in image degradation. Nevertheless, monitoring is mandatory during MRI, especially in a child sedated or in general anesthesia. A monitoring system, made up of commercially available components, was assessed, and its effects on MR (1.5 tesla unit) image quality system determined. Variables monitored included: electrocardiogram and heart rate, (Sirecust 404, ECG cable set MR; Siemens, Enlanger, West Germany); blood pressure via automated sphygmomanometry (Press Mate BP-8800; Colin, Komaki, Japan); and continuous arterial saturation via pulse oximetry (Nellcor 100 E; Nellcor, Inc., Haywood, California). Fluid infusion rate was controlled by means of a plastic deliver (Dial-a-flo; Abbott Labs., Chicago, Illinois). Body temperature was maintained with a heat insulator blanket (Thermadrape, OR Concepts, Inc., Dallas, Texas). The monitoring technique described did not interfere with MRI function or produce image degradation.