The concept of pore pressure parameters has been found convenient to visualize the pore pressure response of saturated soils for various applied stress changes. This paper derives pore pressure parameters that can be utilized in determining the pore pressure response of unsaturated soils. The expressions derived for the estimation of pore-air and pore-water pressures under undrained, isotropic loading are called the B, and B, pore pressure parameters. Measured pore pressures are compared with predicted values. Various factors influencing the proposed pore pressure parameters are discussed. Pore pressure parameter expressions are also derived for the pore-air and pore-water pressures induced as a result of deviator stress changes during undrained loading (i.e., Aa and Aw).