The laser interferometry-based sensing and tracking (LIST) technique can be used to perform real time position measurements of dynamic systems such as robot manipulators. These measurements are necessary to provide accurate calibration and performance measures of robot manipulators. Therefore, it is important that the LIST technique is highly accurate. However, due to the dependence of LIST technique on different sensors and transducer sub-systems, there exists some degree of uncertainty in the measurements obtained. This paper presents the measurement uncertainties associated with the LIST technique. The uncertainties contributed by different sub-systems within the LIST apparatus are analysed. A general expression for uncertainty estimation is also developed. © 2002 Elsevier Science Ltd. All rights reserved.