A method of extracting the system phase from the bispectrum phase, based on a group delay approach, is proposed. The system phase estimation is achieved by relating the bispectral phase to the system group delay function. The proposed method has certain advantages over some of the existing methods. It is applicable for moving average (MA) or autoregressive (AR) or ARMA systems. Even with a few triple correlation lags, its performance is either superior to or at par with those obtained by Lii and Rosenblatt's method or Brillinger's method. The method has been evaluated for ARMA systems.