This paper presents a method for finding the Magnitude Group Delay (MGD) and Phase Group Delay (PGD) functions for complex-valued signals. Algorithms are discussed for reconstructing the complex signals from the partial information of either the phase or magnitude of the Fourier transform of the signals under certain conditions. The high resolution property and the ability to manipulate regions of the spectrum of the MGD are brought out. The utility of the MGD function in identifying the wider bandwidth spectral peak in the vicinity of a narrow bandwidth peak is examined. © 1987.