S wave and P wave velocities when changed to Poisson's ratio are an accurate predictor of pore fluids and lithologies. Amplitude versus Offset (AVO) analysis of single component seismic data, laboratory measurements and 3c seismic data have shown that Poisson's ratio predicts pore fluid better than it predicts lithology. Poisson's ratio versus p wave velocity crossplots from AVO inversions and weIl log data indicate that pore fluid and lithologies fall on distinct trends on the crossplots.