The effects of drifting instrument sensitivity in glow discharge optical emission spectrometry (GD-OES) on instrument calibration were investigated. It was found that for some analytical applications, the rate of drift may be fast relative to the time needed to calibrate the instrument. The results indicate that if this is the case, the validity of calibration may be compromised, introducing analytical bias. Anew drift correction method recently published elsewhere was shown to eliminate any drift-induced calibration difficulties and the associated potential for analytical error. This is important,because drift correction methods that have been traditionally used in OES for decades are not applicable to this particular type of drift. Therefore, the new drift correction method should enhance;the utility of GD-OES for important applications, such as quality control and quality assurance in industry.