In recent years, a variety of sensors have been used for the purpose of real-time robot control. One of them is a computer vision. Despite of the high resolution, increasingly lower cost, high reliability, low weight with low power consumption, and large range of possible light wavelengths, a calibrated 3D visual servoing has not fully matured as a technology yet. In order to widen its use in industrial applications its technological capability must be precisely known. The accuracy and repeatability are two of the crucial parameters in planning of any robotic task. In this paper we describe a procedure to evaluate the 2D the 3D accuracy of a robot stereo vision system consisted of two identical 1 megapixel cameras, and present the results of the evaluation.