Dynamic chromatic Dispersion Compensation (DC) technologies are becoming critical in the design of fbture high speed lightwave systems. While applications in which DC is tuned in predetermined ways, for instance to compensate for the changing acquired dispersion in a reconfigurable optical network [ 11 have been proposed, a more general and significant application of such a technology is to correct for unpredictable variations in the optimal dispersion map due to fiber nonlinearities and signal power variations. The optimal DC of high-speed, nonlinear transmission systems can change dynamically with per channel power [Z], that may occur, for example, due to changes in optical amplifier gain flatness or reconligurable add/drop. This is particularly important at higher bit rates as the dispersion tolerances reduce dramatically (as the square of the bit rate). In addition, the trend to broader bandwidths also reduces the dispersion margin by an amount that is dependent on how well the dispersion slope of the transmission fiber is compensated. The availability of a high-performance dynamic DC technology would alleviate these problems, and in particular, in systems operating in the nonlinear regime, such devices are essential for operation with minimal dispersion margin. This paper reports the demonstration of such a high performance device, including the first demonstration of dynamic compensation of a nonlinear transmission system to maintain nearly optimum performance.