Many rocks in earth formations exhibit transversely isotropic (TI) characteristics. For determining the TI parameter using acoustic logging, Stoneley waves are the only borehole wave mode that has a significant sensitivity to the TI effects, especially when the formation is acoustically slow compared to borehole fluid. This study describes a method for deriving the formation shear-wave TI parameter from the Stoneley wave data acquired by a logging tool. The presence of the tool can substantially alter the Stoneley wave characteristics and must be included in the analysis. In the inversion analysis, Stoneley wave slowness is related to the weighted average of the wave’s dispersion curve over the frequency range occupied by the wave spectrum. This provides a fast method for the inversion. As a processing example, this method has been applied to estimate the shearwave TI parameter profile for the Lewis shale formation in Braggs, Wyoming. The resulting profile delineates the shear-wave anisotropy magnitude and variation for this shale formation.