The traditional compartmentalized approach has been superseded by a multidisciplinary collaborative workflow to build iteratively a subsurface velocity model suitable for detailed and quantitative imaging. Works that have had the most practical industrial application are emphasized, with a bias is away from R & D and toward industrial practice. In Prestack Depth Migration and Velocity Model Building (SEG Geophysics Reprint Series No. 25), the editors bring together works published since the early 1980s, striking a balance between algorithm development and estimation of subsurface velocity and anisotropy parameters. In that time span, a radical change has occurred in the way seismic processing has delivered a subsurface image. The traditional purely compartmentalized approach has been superseded by a multidisciplinary collaborative workflow to build iteratively a subsurface velocity model suitable for detailed and quantitative imaging. Works that have had the most practical industrial application are emphasized rather than assessing all approaches equally. Hence, the bias is away from R & D and toward industrial practice. Because of the distribution of papers in this reprint edition, split between migration algorithm and velocity-estimation techniques, this volume will appeal to processing specialists and interpretation geoscientists alike.