A full three-dimensional prestack depth imaging method that operates on the entire shot gather is presented. The imaging can be performed in areas with lateral as well as vertical velocity variations. The method is suitable for a true 3-D survey where receivers are spread in both horizontal directions. Irregularities in shooting geometry are handled with no extra cost and do not require any special treatment. The imaging is based on the solution of the 3-D eikonal equation. An efficient computational algorithm that utilizes parallel processing was successfully tested on existing hardware.